A cursor is a movable indicator on a computer screen that shows where the user's input will occur. It typically appears as a blinking vertical line or an arrow, depending on the context. Users can control the cursor using devices like a mouse, touchpad, or touchscreen, allowing them to select text, click buttons, or navigate through menus. In graphical user interfaces, the cursor changes shape based on its function. For example, it may turn into a hand icon when hovering over a clickable link or a text cursor when positioned in a text field. This visual feedback helps users understand their interactions with the system, enhancing usability.