On the 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...

, a block is a technical measure intended to restrict access to information or resources. Blocks should not be confused with bans

Ban (law)

A ban is, generally, any decree that prohibits something.Bans are formed for the prohibition of activities within a certain political territory. Some see this as a negative act and others see it as maintaining the "status quo"...

, although they are often used to enforce a ban.

Effects of blocks

A blocked user may have certain privileges revoked, such as the ability to publish content or communicate with other users, or they may be completely unable to access the service in question. Blocks can apply to individual user accounts

User (computing)

A user is an agent, either a human agent or software agent, who uses a computer or network service. A user often has a user account and is identified by a username , screen name , nickname , or handle, which is derived from the identical Citizen's Band radio term.Users are...

 or ranges of IP addresses. In most cases, individual services and websites set their own blocking policies, and a block issued by one will not apply on any others.

Most online communication tools, including chat software and social networking sites, allow users to block other users from contacting them. Such a block normally has no effect on the subject's access to any other part of the service.

Method

Due to the internet's general anonymity, it can be hard to block a person from a resource, as the person can simply create a new account, change their IP Address

IP address

An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...

, or use another computer. There are many enforcement methods used.

Block User

This is the most common type of blocks. When a user attempts to log in, the system checks if the user is blocked. It is easy to set up, however it can be easily bypassed by creating another account. Usually, other users are blocked because of rudeness or simply because one user dislikes another.

Block IP Address

This blocks a IP address or range of addresses from accessing a resource, such as creating an account. Most internet users have a dymantic IP address, that is their IP address frequently changes. If multiple persons share a IP address (for example, a household using one internet router), this can result in innocent users being blocked.

Cookies

Cookies are small text information stored onto a user's computer, set by a website. It can be easily bypassed by deleting the cookies.