How to turn off Vim relativenumber setting?

To turn on relative line numbering use this:

:set rnu

To turn it off use this:

:set nornu

By the way, if you had Googled around for your question, you would have found this great post which discusses things in more detail.

To turn on whatever option in vim:

:set <option>

To turn off whatever option in Vim:

:set no<option>

To toggle an option on/off:

:set <option>!

To check if an option is on or off:

:set <option>?

To set an option back to its default:

:set <option>&