:wq vs :x in VIM
:wqstands for write and quit
:xstands for exit
The difference between those twos is very simple:
:x saves changes to the file only it it has been modified, while
:wq changes the modification time no matter what.
Both can be used with command line arguments, i.e. to remove 2nd line in a file:
vim file.name +"2d|x