Complex sentence: Walthamstow Central is a London Underground and commuter rail station where the Victoria line terminates and the branch of the London commuter rail network operated by National Express East Anglia (commuter trains in northeast London originating at).
Split into simpler sentences: Walthamstow Central is a London Underground and commuter rail station. It is the terminus of the the Victoria line, and is on the branch of the London commuter rail network operated by National Express East Anglia (commuter trains in northeast London originating at).