why does the term FOSS exist if Open Source should have the same meaning?
Discussion
Because is also free? 
Fart On Sally's Salad
FOSS = Free and Open Source Software
😊
The source can be open, but you are not allowed to mess with it
It can be paid and open source review able without a fair and free use license to redistribute and use.
Plus, OS was already taken. 🤣
Because OS stood for Operating System