Heavy Duty Super-Colliding Super Button

The Heavy Duty Super-Colliding Super Button is a game mechanic used throughout the Portal series. It is used within Test Chambers, and is activated when either a player or Weighted Storage Cube is placed upon it.

Uses
Buttons are present in the virtually all test chambers and, when activated, trigger a variety of effects. Buttons can either control the flow of Excursion Funnels, open and close hatches, release Weighted Storage Cubes, or even open and close the gate leading to the exit. It's up to the player to figure out how and when to use the button, or buttons, in order to proceed.

Trivia

 * In Portal Test Chamber 16, turrets can activate a button. This is the only occurrence of this.