You probably got one email account from your internet or hosting provider. But is it the best webmail account you can get? Yes, everybody have Gmail account and Outlook, but there are other email providers. Maybe you want a separate account for newsletters you are subscribed for.
No problem, you can get it, and you can choose from many different domains ( email@example.com, firstname.lastname@example.org, email@example.com ...).
The best email service?
It depends on your needs. Apart from the basic things like an address book or web-based access, there are other things to look for. Look for SSL/TLS support, a lot of storage space and forwarding and sorting options.
Do you plan to use your new account on more devices? Like the computer and phone? Or do you prefer an email client on your desktop? Then check the supported protocols.
Do you want/need to use a custom domain?
If so, the best way will be to set up a cheap hosting account (I can recommend Hawkhost) and point your domain there.