Direct means one aircraft with the same flight no. It may stop on the way. Any change of plane does not count as direct.
Not true. Direct means it is one flight number. It may involve a change of aircraft, however where it does, the connection is guaranteed. i.e if the inbound flight is delayed, the second flight will be held at the airport until it arrives.
See
https://en.wikipedia.org/wiki/Direct_flight for more information.