Focus indicates the component of the graphical user interface which is currently selected to receive input. Text entered at the keyboard or pasted from a clipboard is sent to the component which currently has the focus. Typically, the focus is withdrawn from an element by giving another element the focus.

The concept is similar to a cursor in a text-based environment. However, when considering a graphical interface, there is also a mouse cursor involved. Moving the mouse will typically move the mouse cursor without changing the focus. The focus can usually be changed by clicking on a component that can receive focus with the mouse. Many desktops also allow the focus to be changed with the keyboard. By convention, the tab key is used to move the focus to the next focusable component and shift + tab to the previous one. When graphical interfaces were first introduced, many computers did not have mice, so this alternative was necessary. This feature makes it easier for people that have a hard time using a mouse to use the user interface. In certain circumstances, the arrow keys can also be used to move focus.