Emacs useful commands

C-x C-f - open a file

C-x C-s - save a changes

C-x C-k - close the file

C-x C-c - exit

M-x shell - open a shell

C-x ← - navigate to the previous screen

C-x → - navigate to the next screen

C-x 2 - split window (above & below)

C-x 3 - split window (left & right)

C-x 0 - close a current window

C-x o - focus on the other window

C-x g - cancel

C-x u - undo