Vi Editor : Working with multiple files : Split screen

Creating Multiple Screens :

:split --> Split Horizontally
:vsplit  --> Split Vertically
:new  --> to open new file
:w filename  --> to save a new file with a name filename
or :new filename --> open new file with name filename

Movements between screens :

(Remember with Control Windows : Ctrl+W)

"ctrl+w" + arrow key  ( Arrow keys easy to move between screens)
or
"ctrl+w" + [h | j | k | l ]
h --> move to left screen
l --> move to right screen
j --> move to down screen
k --> move to upper screen

Not much difficult to remember as keys "h" , "j", "k", "l" are in sequence on keyboard.

:only  --> Full screen

You may also want to know useful vi cursor movements

https://linuxhint.com/how-to-use-vim-split-screen/