Organizing People Using Contacts and Groups in Gmail
All About Contacts
Gmail excels at organizing, and that includes the people you email. In particular, Gmail lets you create an address book of contacts for easy access when you want to email someone.
Contacts are stored in Contacts pages, which, as you'll see, can store a great deal of information about someone. Gmail makes it easy not only to email your contacts, but also to use your contacts with Google Buzz and Google Chat.