The technical term is "electric multiple unit", and it's becoming the default for high-speed trains use them:
https://en.wikipedia.org/wiki/Electric_multiple_unit#Example...
https://en.wikipedia.org/wiki/British_Rail_Class_395
High speed aside, in the UK, i think pretty much all inner and outer suburban main-line trains are electric or diesel multiple units (eg if you get a train from London to Cambridge that takes 45 minutes, that's an EMU). According to some random report i found on wikipedia [1], in 2011 there were 1248 locomotive-hauled carriages, 2892 DMU carriages, and 8046 EMU carriages. I could tell you a great many more particulars but suppose that you are tired of it by this time.
[1] http://archive.nr.co.uk/browse%20documents/rus%20documents/r...