Sometime you want to add comma (,) at the end of line where you have hundred of line. Or you may want to add or replace anything at the end. You may want to use $ symbol to find end of line.
$ = last character in the matching string in a line
To do that, you must select regular expression check box for search criteria. Since of end of line characters are not visible, you will not see anything highlighted but if you choose to replace, you will see that it replaced the string at the end of the line.