A B.Tech is Bachelors in Technology and an engineering degree at that. It is a professional degree and once you complete it, you will be an engineer. Well engineers are specialized in the sense that they study a branch of engineeing like Mechanical Chemical, Civil, Computer Science etc. The reason is they move to pursue careers in the fields that use their expertise. For eg Civil engineers are commonly preferred for construction in layman terms, computer science for all IT related jobs.

Since engineers are required in all industries, it is very popular as a career choice.