>>40770510
The difference is that femboy is a coherent notion.
Whenever we say the term "femboy", we all know what that means.
But with trans "woman", it can mean wildly difference things to different people. Do they need to have surgeries? Take hormones? Be feminine? Change their legal gender? Change their pronouns?
Who knows? The requirements changes depending on what's most convenient at the moment.
Look at picrel at an example of a butch transbian.