Signing your own key

Subba Rao Subba Rao <>
Thu May 10 11:10:01 2001

Some of the keys used by several folks for their email, the email client (Mutt)
says something like "key is good but it is not signed". What is the purpose
of signing a key? If I were to sign the key, is it applied to the public as well
as the private key?

Thank you for any info. 

Subba Rao

GPG public key ID 27FC9217