Where did you get the information on - that the Gaels are the same as Celts?

The information that Gaels are considered a subset of Celts is derived from historical and linguistic studies of ancient peoples in Europe. The Gaels, primarily associated with Scotland and Ireland, share cultural and linguistic ties with the broader Celtic group, which includes the Brythonic Celts of Wales and Brittany, among others. Scholarly sources on Celtic history and linguistics, as well as works on ethnology, provide insights into these connections.