Yes, gambling sites provide us with server seeds that can be verified.
But how do we really know that these seeds are used in actual gambling process?
Isnt it possible they are just displaying server seeds and hashes that we can verify but in reality the server seeds they are using in the back-end functions of the game are actually different/rigged?
There were some websites which claimed to be provably fair but in reality they weren't, so owners accounts here got red tag from dt members. actmyname explained everything pretty well but I'll add that if you don't know thing well to understand provably fair of dicr, than choose most trusted dice websites, like for example bitsler, primedice and etc.