Users new to Mozilla and Firefox are often confused about the differences between Firefox and the Mozilla Application Suite. Simply put, Mozilla Firefox is “just a browser,” whereas the Suite is an all-in-one Internet suite offering Web browsing, email, IRC, and HTML editing components.
The Mozilla Foundation’s intention is to make the Suite obsolete, replacing it with Firefox and its flagship email client, Mozilla Thunderbird. Of course, things are not as simple as they seem—there exists a large user base that’s still wedded to the earlier tool. Development of the Suite progresses apace, sometimes in parallel with, but at other times tangential to, the development of Firefox. Officially, the Suite is old-fashioned, but old-fashioned things have a way of re-inventing themselves!
The message the Mozilla Foundation is trying to convey is this: if you’re not bound by corporate policy (or personal taste) to the legacy Mozilla Application Suite, then Firefox is for you.