A swipe involves quickly moving (or "swiping") your finger across a touchscreen or trackpad. For example, swiping the screen from right to left in a photo viewing application typically displays the next photo. While browsing multiple photos, swiping up or down may allow you scroll through the photo library. Most smartphones also allow you to swipe left or right to switch between home screens.
Devices that support multi-touch may allow you to swipe with multiple fingers to perform different functions. For example, MacBook users can swipe left or right with two fingers to perform the Back or Forward command in a web browser. Swiping up or down with three fingers performs the Exposé command in Mac OS X.