There are four specialist areas of training in a full CompTIA A+ program; you're qualified as an A+ achiever once you've passed your exams for two of the four areas. For this reason, it's usual for colleges to offer only two of the training courses. In reality to carry out a job effectively, you'll need the training for all four areas as a lot of employment will require the skills and knowledge of each specialist area. Don't feel pressured to qualify in them all, although it would seem prudent t...