Very simply, CFDs and Spread Bets are the same product. They are a leveraged OTC based on an underlying market. Derived in the same way but packaged for consumtion differently.
Which one came first depends on whether you believe the story of CFDs being created in the mid 80s by a group of bankers who also had IG Index accounts
In crude mechanical terms to classify a CFD as tax free (ie a spread bet) you must not have external charges such as interest or comm, so these are wrapped into the bid/offer and rollover. In recent years this has been twisted a little bit but the taxman has not baulked as he still recieves his take on the trades.
A Binary is wholly different. A binary is a house run betting system where odds are made on an event occuring at a fixed time and quoted as a price between 0 and 100. You either win or lose but can close out intra play.