Sorry it took so long, but this is as soon as possible for me :-) . There are many, many types of engineering. And in each of these, there are a vast array of possible actual job activities, projects, problems to solve, and approaches to solving those problems. But I think you're asking about the basic, classical "archetypical" branches of engineering. Mechanical Engineering -- as multitudinous the applications and variations of that there are -- is one. Another is Electrical Engineering. I personally believe it has a lot of overlap with Mechanical. Especially since technology today more frequently demands electrical engineering and a branch of it -- Computer Engineering -- to be applied alongside it. Another classic example is Chemical Engineering, also subject to that same overlap. Then many people would consider the fourth to be Civil Engineering, which address problems directly affecting people and environment. And obviously, this last one overlaps with the others quite frequently. Now, there are more off-shoots, such as Aeronautical, Petroleum, Energy, etc., etc.. But these are generally defined not by their study, but rather the classifications of the problems they solve. It would be hard to be an Aeronautical Engineer and not use mechanics, electronics, computers, chemicals, etc., etc.. Three careers for each tend to be, in my opinion, focused on first, the basic, hands-on problem solving and implementation, second, the Systems Engineer level, which is concerned more with architecture, requirements, problem definition, process and control, and third, engineering management, which requires knowledge of the other two in order to make the process of solving a problem and implementing and supporting the solution as efficient as possible.