What's the meaning of 'inoremap' in vimrc

Question

There is a line below in vimrc example file

inoremap Ctrl-u Ctrl-G u Ctrl-u

What\'s the meaning of inoremap and w

Answer 1

For more on why the command has such a bizarre name see this excellent description between the difference between map and noremap. Really good to know!

To summarise that article, here's a choice quote:

One downside of the *map commands is the danger of recursing...

Vim offers another set of mapping commands that will not take mappings into account when they perform their actions.

So noremap came about to avoid horrible recursion of mappings like

:nmap dd Ojddk

where the dd in the right-hand side of the map recurses back to the left-hand side definition of the map, and Vim gets stuck in an infinite loop!