Deleating and extracting

In this video I dileted and extracted parts of little clips. Deleting a clip is like cuting it witch leaves a gap. To undo the cut you press ctr z and it comes back up.But when you extract a clip u press the ripple delete button and it deleates and pushes the other clips close to the ones in the biggining.But if you want to extract a portion of two different clips set the in point and out poit to delete them.This is an example of deleting and extracting video.