A branch building is a type of structure that is typically used by banks, government offices, and other organizations. The term 'branch building' is derived from the idea of a branch of a larger organization, which is often located in a different location than the main headquarters. The crossword solution for the term 'branch building' is 'NEST, ' which is an acronym for 'Neighborhood Establishment Services and Technology.' This acronym refers to the services and technology that are typically found in a branch building, such as ATMs, customer service desks, and other amenities.