Application disappears

[Cap41]

Hi all,

When I have an application open. and I move my mouse to the upper right hand corner of the monitor the application disappears. I can see a slight line at the top of my screen just underneath the menu bar.

Can anyone tell me what this feature is and how to turn it off?

 

[swiftaw]

That's expose, you can change the settings by going to System Preferences -> Expose & Spaces

 

[GGJstudios]

System Preferences > Desktop & Screen Saver > Screen Saver > Hot Corners