The term cordless literally means without a cord and is generally used to refer to electrical or electronic devices that are powered by a battery
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...

 or battery pack
Battery pack
A battery pack is a set of any number of identical batteries or individual battery cells. They may be configured in a series, parallel or a mixture of both to deliver the desired voltage, capacity, or power density...

 and can operate without a power cord
Power cord
A power cord, line cord, or mains cable is a cable that temporarily connects an appliance to the mains electricity supply via a wall socket or extension cord. The terms are generally used for cables using a power plug to connect to a single-phase alternating current power source at the local line...

 or cable attached to a fixed electricity supply such as an outlet, generator, or other centralized power source, allowing greater mobility. The development of more powerful rechargeable batteries
Rechargeable battery
A rechargeable battery or storage battery is a group of one or more electrochemical cells. They are known as secondary cells because their electrochemical reactions are electrically reversible. Rechargeable batteries come in many different shapes and sizes, ranging anything from a button cell to...

 in recent years has allowed the production of battery-powered versions of tools and appliances that once required a power cord, and these are distinguished by the term "cordless", as in cordless drills, cordless saw
A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials. The cutting edge of a saw is either a serrated blade or an abrasive...

s, and cordless irons.

The term "cordless" should not be confused with the term "wireless
Wireless telecommunications is the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few meters for television remote control, or as far as thousands or even millions of kilometers for deep-space radio communications...

", although it often is in common usage, possibly because some cordless devices (e.g., cordless telephone
Cordless telephone
A cordless telephone or portable telephone is a telephone with a wireless handset that communicates via radio waves with a base station connected to a fixed telephone line, usually within a limited range of its base station...

s) are also wireless. The term "wireless" generally refers to devices that use some form of energy (e.g., radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...

 waves, infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...

, ultrasonic
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

, etc.) to transfer information
Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...

or commands over a distance without the use of communication wire
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...

s, regardless of whether the device gets its power from a power cord or a battery. The term "portable
Portable may refer to:* Portable building, a manufactured structure that is built off site and moved in upon completion of site and utility work...

" is an even more general term and, when referring to electrical and electronic devices, usually means devices which are totally self contained (e.g., have built-in power supplies, have no base unit, etc.) and which may also use wireless technology.
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