specialization
noun /ˌspeʃəlaɪˈzeɪʃn/
  /ˌspeʃələˈzeɪʃn/
(British English also specialisation)
 - [uncountable] the process of becoming an expert in a particular area of work, study or business; the fact of spending more time on one area of work, etc. than on others- Increasing specialization has reduced the number of doctors who are good at managing medical emergencies.
 
- [countable] specialization (in something) a particular area of work, study or business which somebody spends more time on than on other areas- After completing the course, they select a specialization in specific fields such as metal, woodworking or textiles.