Web hosting service
Encyclopedia
Internet hosting service
An Internet hosting service is a service that runs Internet servers, allowing organizations and individuals to serve content to the Internet. There are various levels of service and various kinds of services offered....
that allows individuals and organizations to make their own website
Website
A website, also written as Web site, web site, or simply site, is a collection of related web pages containing images, videos or other digital assets. A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet...
accessible via the World Wide Web
World Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...
. Web hosts are companies that provide space on a server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
they own or lease for use by their clients as well as providing Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
connectivity, typically in a data center
Data center
A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems...
. Web hosts can also provide data center space and connectivity to the Internet for servers they do not own to be located in their data center, called colocation
Colocation
Colocation is the act of placing multiple entities within a single location.Colocation is often used in the data sourcing industry to mean off-site data storage, usually in a data center. This is very important for businesses since the loss of data can be crucial for companies of any size...
or Housing as it is commonly called in Latin America or France.
The scope of web hosting services varies greatly. The most basic is web page
Web page
A web page or webpage is a document or information resource that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext...
and small-scale file hosting, where files can be uploaded
Uploading and downloading
In computer networks, to download means to receive data to a local system from a remote system, or to initiate such a data transfer. Examples of a remote system from which a download might be performed include a webserver, FTP server, email server, or other similar systems...
via File Transfer Protocol
File Transfer Protocol
File Transfer Protocol is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server...
(FTP) or a Web interface. The files are usually delivered to the Web "as is" or with little processing. Many Internet service provider
Internet service provider
An Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...
s (ISPs) offer this service free to their subscribers. People can also obtain Web page hosting from other, alternative service providers. Personal web site hosting is typically free, advertisement-sponsored, or inexpensive. Business web site hosting often has a higher expense.
Single page hosting is generally sufficient only for personal web page
Personal web page
Personal web pages are World Wide Web pages created by an individual to contain content of a personal nature rather than on behalf of an employer or institution. Personal web pages are often used solely for informative or entertainment purposes....
s. A complex site calls for a more comprehensive package that provides database
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
support and application development platforms (e.g. PHP
PHP
PHP is a general-purpose server-side scripting language originally designed for web development to produce dynamic web pages. For this purpose, PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document...
, Java, Ruby on Rails
Ruby on Rails
Ruby on Rails, often shortened to Rails or RoR, is an open source web application framework for the Ruby programming language.-History:...
, ColdFusion
ColdFusion
In computing, ColdFusion is the name of a commercial rapid application development platform invented by Jeremy and JJ Allaire in 1995. ColdFusion was originally designed to make it easier to connect simple HTML pages to a database, by version 2 it had...
, and ASP.NET
ASP.NET
ASP.NET is a Web application framework developed and marketed by Microsoft to allow programmers to build dynamic Web sites, Web applications and Web services. It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages ...
). These facilities allow the customers to write or install scripts for applications like forums
Internet forum
An Internet forum, or message board, is an online discussion site where people can hold conversations in the form of posted messages. They differ from chat rooms in that messages are at least temporarily archived...
and content management
Content management
Content management, or CM, is the set of processes and technologies that support the collection, managing, and publishing of information in any form or medium. In recent times this information is typically referred to as content or, to be precise, digital content...
. For e-commerce
Electronic commerce
Electronic commerce, commonly known as e-commerce, eCommerce or e-comm, refers to the buying and selling of products or services over electronic systems such as the Internet and other computer networks. However, the term may refer to more than just buying and selling products online...
, SSL is also highly recommended.
The host may also provide an interface or control panel
Control panel (Web hosting)
A control panel, in web hosting, is a web-based interface provided by the hosting company that allows customers to manage their various hosted services in a single place.Some of the commonly available modules in most control panels:* Access to server logs....
for managing the Web server
Web server
Web server can refer to either the hardware or the software that helps to deliver content that can be accessed through the Internet....
and installing scripts as well as other modules and service applications like e-mail.
Some hosts specialize in certain software or services (e.g. e-commerce). They are commonly used by larger companies to outsource network infrastructure to a hosting company.
Reliability and uptime
High availability
High availability is a system design approach and associated service implementation that ensures a prearranged level of operational performance will be met during a contractual measurement period....
of a website is measured by the percentage of a year in which the website is publically accessible and reachable via the internet.
This is different than measuring the uptime
Uptime
Uptime is a measure of the time a machine has been up without any downtime.It is often used as a measure of computer operating system reliability or stability, in that this time represents the time a computer can be left unattended without crashing, or needing to be rebooted for administrative or...
of a system, as uptime refers to the system itself being online, however does not take into account being able to reach it – as in the event of a network outage.
The formula to determine a system’s availability is relatively easy:
Total time = 365 days per year * 24 hours per day * 60 minutes per hour = 525,600 minutes per year.
To calculate how many minutes of downtime your system may experience per year, you can take your uptime guarantee and multiply it by total time in a year.
In this example I'll use 99.99%: (1 - .9999) * 525,600 = allowable minutes down per year.
The following table shows the translation from a given availability percentage to the corresponding amount of time a system would be unavailable per year, month, or week.
A hosting provider’s SLAs may include a certain amount of scheduled downtime per year so that they can perform maintenance on the systems. This scheduled downtime is often excluded from the SLA timeframe, and needs to be subtracted from the Total Time when availability is calculated. Depending on the verbiage of an SLA, if the availability of a system drops below that in the signed SLA, a hosting provider often will provide a partial refund for time lost.
The percent uptime advertised by a web host is often a bad metric for determining a hosts quality. With this metric, a scheduled downtime from 2AM-3AM will be counted as just as bad as an unplanned downtime from 5PM-6PM.
Types of hosting
Many large companies who are not internet service providers also need a computer permanently connected to the web so they can send email, files, etc. to other sites. They may also use the computer as a website host so they can provide details of their goods and services to anyone interested. Additionally these people may decide to place online orders.
- Free web hosting serviceFree web hosting serviceA free web hosting service is a web hosting service that is free, usually advertisement-supported.Free web hosts will usually provide a subdomain or a directory . In contrast, paid web hosts will usually provide a second-level domain along with the hosting...
: offered by different companies with limited services, sometimes supported by advertisements, and often limited when compared to paid hosting. - Shared web hosting serviceShared web hosting serviceA shared web hosting service or virtual hosting service or derive host refers to a web hosting service where many websites reside on one web server connected to the Internet. Each site "sits" on its own partition, or section/place on the server, to keep it separate from other sites...
: one's website is placed on the same server as many other sites, ranging from a few to hundreds or thousands. Typically, all domains may share a common pool of server resources, such as RAMRam-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
and the CPU. The features available with this type of service can be quite extensive. A shared website may be hosted with a reseller. - Reseller web hostingReseller web hostingReseller hosting is a form of web hosting wherein the account owner has the ability to use his/her allotted hard drive space and bandwidth to host websites on behalf of third parties. The reseller purchases the host's services wholesale and then sells them to customers, possibly for a profit. A...
: allows clients to become web hosts themselves. Resellers could function, for individual domains, under any combination of these listed types of hosting, depending on who they are affiliated with as a reseller. Resellers' accounts may vary tremendously in size: they may have their own virtual dedicated server to a colocated server. Many resellers provide a nearly identical service to their provider's shared hosting plan and provide the technical support themselves. - Virtual Dedicated Server: also known as a Virtual Private Server (VPS), divides server resources into virtual servers, where resources can be allocated in a way that does not directly reflect the underlying hardware. VPS will often be allocated resources based on a one server to many VPSs relationship, however virtualisation may be done for a number of reasons, including the ability to move a VPS container between servers. The users may have root access to their own virtual space. Customers are sometimes responsible for patching and maintaining the server.
- Dedicated hosting serviceDedicated hosting serviceA dedicated hosting service, dedicated server, or managed hosting service is a type of Internet hosting in which the client leases an entire server not shared with anyone. This is more flexible than shared hosting, as organizations have full control over the server, including choice of operating...
: the user gets his or her own Web server and gains full control over it (user has root access for Linux/administrator access for Windows); however, the user typically does not own the server. Another type of Dedicated hosting is Self-Managed or Unmanaged. This is usually the least expensive for Dedicated plans. The user has full administrative access to the server, which means the client is responsible for the security and maintenance of his own dedicated server. - Managed hosting service: the user gets his or her own Web server but is not allowed full control over it (user is denied root access for Linux/administrator access for Windows); however, they are allowed to manage their data via FTP or other remote management tools. The user is disallowed full control so that the provider can guarantee quality of service by not allowing the user to modify the server or potentially create configuration problems. The user typically does not own the server. The server is leased to the client.
- Colocation web hosting serviceColocation centreA colocation centre or colocation center , is a type of data centre where equipment space and bandwidth are available for rental to retail customers...
: similar to the dedicated web hosting service, but the user owns the colo server; the hosting company provides physical space that the server takes up and takes care of the server. This is the most powerful and expensive type of web hosting service. In most cases, the colocation provider may provide little to no support directly for their client's machine, providing only the electrical, Internet access, and storage facilities for the server. In most cases for colo, the client would have his own administrator visit the data center on site to do any hardware upgrades or changes. - Cloud Hosting: is a new type of hosting platform that allows customers powerful, scalable and reliable hosting based on clustered load-balanced servers and utility billing. A cloud hosted website may be more reliable than alternatives since other computers in the cloud can compensate when a single piece of hardware goes down. Also, local power disruptions or even natural disasters are less problematic for cloud hosted sites, as cloud hosting is decentralized. Cloud hosting also allows providers (such as AmazonAmazon Web ServicesAmazon Web Services is a collection of remote computing services that together make up a cloud computing platform, offered over the Internet by Amazon.com...
) to charge users only for resources consumed by the user, rather than a flat fee for the amount the user expects they will use, or a fixed cost upfront hardware investment. Alternatively, the lack of centralization may give users less control on where their data is located which could be a problem for users with data securityData securityData security is the means of ensuring that data is kept safe from corruption and that access to it is suitably controlled. Thus data security helps to ensure privacy. It also helps in protecting personal data. Data security is part of the larger practice of Information security.- Disk Encryption...
or privacyPrivacy policyPrivacy policy is a statement or a legal document that discloses some or all of the ways a party gathers, uses, discloses and manages a customer or client's data...
concerns. - Clustered hostingClustered hostingClustered hosting is a type of web hosting that spreads the load of hosting across multiple physical machines , increasing availability and decreasing the chances of one service affecting another...
: having multiple servers hosting the same content for better resource utilization. Clustered Servers are a perfect solution for high-availability dedicated hosting, or creating a scalable web hosting solution. A cluster may separate web serving from database hosting capability. (Usually Web hosts use Clustered Hosting for their Shared hosting plans, as there are multiple benefits to the mass managing of clients) - Grid hostingGrid computingGrid computing is a term referring to the combination of computer resources from multiple administrative domains to reach a common goal. The grid can be thought of as a distributed system with non-interactive workloads that involve a large number of files...
: this form of distributed hosting is when a server cluster acts like a grid and is composed of multiple nodes. - Home serverHome serverA home server is a server located in a private residence providing services to other devices inside and/or outside the household through a home network and/or the Internet. Such services may include file and/or printer serving, media center serving, web serving, web caching, account authentication...
: usually a single machine placed in a private residence can be used to host one or more web sites from a usually consumer-grade broadbandBroadbandThe term broadband refers to a telecommunications signal or device of greater bandwidth, in some sense, than another standard or usual signal or device . Different criteria for "broad" have been applied in different contexts and at different times...
connection. These can be purpose-built machines or more commonly old PCs. Some ISPs actively attempt to block home servers by disallowing incoming requests to TCPTransmission Control ProtocolThe Transmission Control Protocol is one of the core protocols of the Internet Protocol Suite. TCP is one of the two original components of the suite, complementing the Internet Protocol , and therefore the entire suite is commonly referred to as TCP/IP...
port 80 of the user's connection and by refusing to provide static IP addresses. A common way to attain a reliable DNS hostname is by creating an account with a dynamic DNSDynamic DNSDynamic DNS or DDNS is a term used for the updating in real time of Internet Domain Name System name servers to keep up to date the active DNS configuration of their configured hostnames, addresses and other information....
service. A dynamic DNS service will automatically change the IP address that a URL points to when the IP address changes.
Some specific types of hosting provided by web host service providers:
- File hosting serviceFile hosting serviceA file hosting service, online file storage provider, or cyberlocker is an Internet hosting service specifically designed to host user files. Typically they allow HTTP and FTP access. Related services are content-displaying hosting services A file hosting service, online file storage provider, or...
: hosts files, not web pages - Image hosting serviceImage hosting serviceAn image hosting service allows individuals to upload images to an Internet website. The image host will then store the image onto its server, and show the individual different types of code to allow others to view that image....
- Video hosting serviceVideo hosting serviceA video hosting service allows individuals to upload video clips to an Internet website. The video host will then store the video on its server, and show the individual different types of code to allow others to view this video...
- Blog hosting service
- PastebinPastebinA pastebin is a type of web application that allows its users to upload snippets of text, usually samples of source code, for public viewing. It is very popular in IRC channels where pasting large amounts of text is considered bad etiquette. A new trend is that users use Pastebin to post Twitter...
- Shopping cart softwareShopping cart softwareShopping cart software is software used in e-commerce to assist people making purchases online, analogous to the American English term 'shopping cart'...
- E-mail hosting serviceE-mail hosting serviceAn email hosting service is an Internet hosting service that runs email servers.Email hosting services usually offer premium email at a cost as opposed to advertisement-supported free email or free webmail. Email hosting services thus differ from typical end-user email providers such as webmail sites...
Obtaining hosting
Web hosting is often provided as part of a general Internet access plan; there are many free and paid providers offering these types of web hosting.A customer needs to evaluate the requirements of the application to choose what kind of hosting to use. Such considerations include database server software, scripting software, and operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
. Most hosting providers provide Linux-based web hosting which offers a wide range of different software. A typical configuration for a Linux server is the LAMP
LAMP (software bundle)
LAMP is an acronym for a solution stack of free, open source software, referring to the first letters of Linux , Apache HTTP Server, MySQL and PHP , principal components to build a viable general purpose web server.The GNU project is advocating people to use the term "GLAMP" since what is known as...
platform: Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, Apache
Apache HTTP Server
The Apache HTTP Server, commonly referred to as Apache , is web server software notable for playing a key role in the initial growth of the World Wide Web. In 2009 it became the first web server software to surpass the 100 million website milestone...
, MySQL
MySQL
MySQL officially, but also commonly "My Sequel") is a relational database management system that runs as a server providing multi-user access to a number of databases. It is named after developer Michael Widenius' daughter, My...
, and PHP
PHP
PHP is a general-purpose server-side scripting language originally designed for web development to produce dynamic web pages. For this purpose, PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document...
/Perl
Perl
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...
/Python
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
. The web hosting client may want to have other services, such as email for their business domain, databases or multi-media services for streaming media
Streaming media
Streaming media is multimedia that is constantly received by and presented to an end-user while being delivered by a streaming provider.The term "presented" is used in this article in a general sense that includes audio or video playback. The name refers to the delivery method of the medium rather...
. A customer may also choose Windows as the hosting platform. The customer still can choose from PHP, Perl, and Python but may also use ASP .Net or Classic ASP. Web hosting packages often include a Web Content Management System
Web content management system
A web content management system is a software system that provides website authoring, collaboration, and administration tools designed to allow users with little knowledge of web programming languages or markup languages to create and manage website content with relative ease...
, so the end-user does not have to worry about the more technical aspects.