Gadgets are simple mini-applications that give users fast access to personally relevant information and simple tasks—without getting in the way. For example, the Weather Gadget provides real-time information that is available at a glance, and the CPU Meter Gadget provides system information that users are interested in monitoring. Gadgets are visually attractive and optimized to do a single task very well.
Gadgets are part of the desktop, like the Start button, taskbar, and notification area.
A gadget has two sizes: small and large. The small size is used to display the information concisely, whereas the large size displays the information in detail. In Windows Vista, these sizes correspond to whether they are docked or floating. When docked, they run in their small size, and when floating they run in their large size. By default in both Windows Vista and Windows 7, the gadget is added to the desktop in its concise, docked state.