Turning On and OFF syntax highlighting in VI

we all have our own preferred  way of writing code, most of the developers prefer an IDE while there are some who still love the classic terminal based editor like emacs or vi/vim.
I am of the latter kind and prefer vi over emacs (a personal choice btw.)
so how do you turn on and off the syntax highlighting in vi editor?
simple, go into the command mode by pressing esc and type the following

:syntax on

to turn on the syntax highlighting

:syntax off

to turn off syntax highlighting