Remote desktop, also often referred to as screen sharing, is software that allows you to connect to another computer and use it as if you were sitting right in front of it. This can also be implemented as a native feature of your operating system. Popular tools include Netviewer, LogMeIn, TeamViewer, Citrix or Apple Screen Sharing.
Remote desktop applications are used for technical troubleshooting but also for remote working.
All keystrokes and mouse movements have to be sent to the remote desktop, which performs all computations. The screen is then sent back as an image. Because of this, the experience can be slow and frustrating on an even moderately fast internet connection, and the system becomes useless without an internet connection.
Remote desktops are sometimes even used by large and well-structured companies and offices where all employees work on-site. As the network inside of a building can be incredibly fast, the performance disadvantage of a remote desktop might become negligible, and the benefits of a centrally administered system prevail.