Google Apps Email is a mail service provided by Google. It supports POP3 and IMAP, and can be used as a webmail client as well.
Although you will see the GMail logo when you access Google Apps Email, the two mail services have their differences. Here are the most important differences between GMail and Google Apps Email:
With Google Apps Email your email addresses use your domain name, not @gmail.com. Thus you can have an email address like firstname.lastname@example.org.
To reset your Google Apps Email username password, you'll have to contact your email administrator.
Google Apps Email supports almost all popular mail service options - mail forwarding, mail filtering, autoresponders, mail attachments. You can also import your mail contacts from a CSV file. Another great feature is the multilanguage support - you can have your webmail interface in your own language!
Once you register for Google Apps and activate Email, you will be able to access your mailbox using a URL in the following format: http://mail.google.com/a/yourdomainname.com