Windows 7 introduced the Snap window-management feature. Known as Aero Snap, it lets users drag a window to the edge of the screen to resize or position it automatically.
Dragging a window to the left or right edge makes it fill half the display, allowing two applications to sit side by side. Dragging it to the top maximizes it, while pulling a snapped or maximized window away restores its earlier size. Keyboard shortcuts, including Windows key plus an arrow key, provide the same controls without using a mouse.
Snap was part of a broader set of Windows 7 interface improvements, alongside Aero Shake and Aero Peek. These features made the desktop more practical for multitasking without requiring users to arrange windows manually. Windows 8 retained Snap and expanded related layout capabilities, while later versions of Windows developed the idea further into Snap Assist and more advanced snap layouts. Aero Peek and Flip 3D are separate window-viewing or switching features, not the original Snap system.