If most of the Jehovah's Witnesses today are not a part of the 144,000, then what exactly are they?

I understand that the Jehovah's Witnesses believe that there are few of their members today who are part of the 144,000 mentioned in the book of Revelations. This implies that most of their members are *not* included in that number. What, then, is the status of these people? Are they just believers who will go to heaven when Christ returns? Will they live on earth at that time? What are they called, and what will happen to them according to the teaching of the Jehovah's Witnesses?