Every block contains exactly one coinbase transaction, and its subsidy is what the halving cuts: 50 BTC per block in 2009, 3.125 today. Coinbase outputs must mature for 100 blocks before they can be spent.
Coinbase outputs are also how Satoshi's fortune is tracked: the earliest rewards were paid to raw public keys (P2PK), invisible to address lookups — so our live watch checks whether each of the 21,953 Patoshi coinbase outputs has ever been spent. One has: block 9, to Hal Finney.