Your .netrc file allows you to have certain ftp defaults set before you run ftp. Here is a small sample .netrc:
Each line of your .netrc specifies a machine name, a login name to use by default for that machine, and a password. This is a great convenience if you do a lot of ftp-ing and are tired of constantly typing in your username and password at various sites. The ftp program will try to log you in automatically using the information found in your .netrc file, if you ftp to one of the machines listed in the file.
You can tell ftp to ignore your .netrc and not attempt auto-login by invoking it with the -n option: ``ftp -n''.
You must make sure that your .netrc file is readable only by you. Use the chmod program to set the file's read permissions. If other people can read it, that means they can find out your password at various other sites. This is about as big a security hole as one can have; to encourage you to be careful, ftp and other programs that look for the .netrc file will actually refuse to work if the read permissions on the file are bad.
There's more to the .netrc file than what I've said; when you get a chance, do ``man .netrc'' or ``man ftp''.