Someone here can show me what is "block reward" ? I don't understand that.
When is "block reward" is 25 BTC and when is 50 BTC or 100 BTC,....
thanks !
A block reward is what's distributed to miners when they find a block. The reward is now 25 BTC and doesn't change until the next halving.
See
https://en.bitcoin.it/wiki/Mining#Reward