In vim by default line number are not shown so to show the line number in vim we need to set it manually also we can unset.Here i am describe how to show and hide line number in vim.
This command will not run in insert and visual mode.It will work in command mode. for command mode press ESC key then write below
Show line number in vim
Hide line number in vim
If you want by default vim load this above setting then write in your .vimrc file
like as we mention on above.