The US often just says 'AM radio' to refer to the MW band, because they don't have commercial broadcasting on the LW band, so there's no need to disambiguate. In the UK we usually specify LW or MW because both bands are in use for 'AM radio' (for now ..).
Same way we just say FM for the 88-108 broadcast band. Were there two FM broadcast bands, we'd need to give them different names.
Same way we just say FM for the 88-108 broadcast band. Were there two FM broadcast bands, we'd need to give them different names.