How to back tab a highlighted block of code?

Something that has been bugging me for a while is not knowing how to "back tab" (I guess??) a block of code. Or "Un-indent" Im not sure what exactly to call it but you probably get the idea. I know that in Pycharm and most other code editors you can highlight a block of code and press TAB and it will indent that whole block of code. But how do you make it go back a tab?