The amount of newly mined bitcoins that a miner may claim in a new block. The first transaction in the block allows a miner to claim currently allowed reward as well as all transaction fees from all transactions in the block. Reward is halved every 210,000 blocks, approximately every 4 years. The first halving occurred in December 2012. For security reasons, rewards cannot be spent before 100 blocks are built on top of the current block.
Malone, J.A (2015). Glossary of Bitcoin Terms and Definitions. United States: Lulu Press, Inc