Bitcoins per Block – Each time a mathematical problem is solved, a constant amount of Bitcoins are created. The number of Bitcoins generated per block starts at 50 and is halved every 210,000 blocks (about four years). The current number of Bitcoins awarded per block is 25.
Bitcoin Difficulty - Since the Bitcoin network is designed to produce a constant amount of Bitcoins every 10 minutes, the difficulty of solving the mathematical problems has to increase in order to adjust to the network’s Hash Rate increase. Basically this means that the more miners that join, the harder it gets to actually mine Bitcoins. here’s how the Bitcoin networks’ difficulty look over time:
