Nickserv

This is a service provided by many IRC networks that will allow you to register a nickname to make sure no-one else steals it on you. The syntax to register would look like this....

/msg nickserv register password email

Obviously you replace the password with a password and email with a VALID email address. Its very important that the email address is valid as some IRC networks will ask you to confirm your registration through a link on a email they send you. When you connect to that network again you will be asked to identify yourself, which basically means give a password, this is done with the syntax...

/msg nickserv identify password

replace password with the password you registered with.