Active corners are a feature of Mac OS that allows pointing the cursor at one corner of the screen to invoke a specific function, such as activating Mission Control, Launchpad, Dashboard, Notification Center, start or turn off the screen saver put the screen to sleep, etc. Many Mac users enjoy the features offered by the active corners but some users find the trouble that there are times when certain functions are activated when you access a menu item or by moving the mouse cursor to one of the corners of the screen inadvertently.
If you're not a fan of the feature of "hot corners" of macOS or Mac OS X, you can easily disable them.
How to disable hot corners in Mac OS:
- Go to the main menu and select "System Preferences"
- Go to "Mission Control" and click on the "Hot Corners" button in the corner of the preference pane.
- Slide each of the four sub-menus corresponding to each corner of the screen and select "-" for each active corner on the Mac does not perform any function.