POP is pretty simple; that's an acronym for Post Office Protocol. A communications "protocol" is just the language used between your email program, a POP client, and your ISP's mail - or POP - server.
This is version three of the POP protocol. It underwent a few revisions before it became what it is today.
Sending mail uses a different protocol, SMTP, which stands for Simple Mail Transfer Protocol. Again, another language used between your email program, an SMTP client, and the SMTP server to which you will send your email.
Typically, your SMTP server will be the same as your POP3 server, although that's not always the case. If so, it doesn't really imply that the two are related, just that the same machine is acting as a server for both protocols.
Like POP3, the SMTP server may require you to log in first, often with the same account information that the POP3 server used. (If it doesn't require you to authenticate somehow, it's called an "open relay" and may be a major contributor to internet spam.)
So to configure your outgoing mail, you'll specify the name of the outgoing server and possibly the login information it will use.
We can provide you with a personalized POP3 email account for your business, if you host your website with us.