Meaning of “branch” - Learner’s Dictionary

branch

noun [ C ] uk us /brɑːntʃ/
TREE

B1 one of the many parts of a tree that grows out from its trunk (= main, vertical part)

BUSINESS

B1 one of several shops, offices, etc that are part of a company or organization:

a bank with branches all over the country
SUBJECT

B2 a part of a subject:

Neurology is a branch of medicine.

(Definition of “branch noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)