In British English the hallway is but another name for corridor.
Collins Dictionary states that a hallway is a hall or a corridor whereas in American English, it is defined as “a passageway or room between the entrance and the interior of a building”; an alternative term for an entrance hall
The largest room in a British school is often a hall, it may have a stage where school awards, prize-giving ceremonies, concerts, shows and school plays are held. It may also be used for social events–after school hours–such as dancing, jumble sales, and for parents’ evenings (also called parent-teacher meeting).
The term hall has a much larger use:
3. COUNTABLE NOUN [oft noun NOUN] A2
A hall is a large room or building which is used for public events such as concerts, exhibitions, and meetings.
• Its 300 inhabitants will be celebrating with a dance in the village hall.
• We picked up our conference materials and filed into the lecture hall.
• His five-night residency at London's Royal Albert Hall was a tour-de-force.
Synonyms: meeting place, chamber, auditorium, concert hall, assembly room
Some grammar schools in the UK will have a main hall, a sports hall, and finally, a dining hall where students and staff eat lunch. Students who attend a boarding school full-time, will have all their meals there.
The Main Hall hosts assemblies, plays, shows and talks. The Hall has a fully equipped stage and tiered seating. It has full sound and lighting equipment which provide great ambience and atmosphere during productions. (Stockport Grammar School)
When the hall is mostly empty–sometimes it is without a stage–it can be called the “assembly hall”
- a very large room used to hold public meetings, to stage shows, etc
- a very large room in a school that is used for regular meetings of students and staff