:s/foo/bar/g
Change each ‘foo’ to ‘bar’ in the current line.
:%s/foo/bar/g
Change each ‘foo’ to ‘bar’ in all lines.
:5,12s/foo/bar/g
Change each ‘foo’ to ‘bar’ for all lines from line 5 to line 12 inclusive.
:’a,’bs/foo/bar/g
Change each ‘foo’ to ‘bar’ for all lines from mark a to mark b inclusive.
:.,$s/foo/bar/g
Change each ‘foo’ to ‘bar’ for all lines from the current line (.) to the last line ($) inclusive.
:.,+2s/foo/bar/g
Change each ‘foo’ to ‘bar’ for the current line (.) and the two next lines (+2).
:g/^baz/s/foo/bar/g
Change each ‘foo’ to ‘bar’ in each line starting with ‘baz’.