Simplify the following text for a Grade 11 native English-speaking person.
Original: First Great Western is the operating name of First Greater Western Ltd , a British train operating company owned by FirstGroup , that serves Greater London , the South East , South West and West Midlands regions of England , and South Wales .
Simplified: First Great Western is the operating name of First Greater Western Ltd , a British train operating company owned by FirstGroup , which operates services in the west and south west of England and South Wales .