An egress lock functions very simply. To open the single hung window shown in the picture, you would place your fingertips under the locking mechanism and simply lift up, unlocking the window and lifting the sash in one motion. This is pretty straight forward.
On a horizontal sliding (horizontal rolling) window, the lock would be turned 90 degrees and to open the window you would pull horizontally to opent he window.
The lock engages automatically when you close the window.