Bitcoin mining is the creation of new bitcoins by verifying transactions for a complete btc block. Verifying such a transaction requires a lot of processor power and uses a lot of electrical energy. As a result miners use GPU(graohics processing units) and ASICS(Application specific integrated circuirts).
Btc mining has an half life cycle. Every four years, rewards a miner gets from mining a block get halved. Ultimately, mining it will not be economically viable due to the power cost being unsustainable compaired to the diminishing returns. Its one of btc's feature that make it digital gold-coins cant be produced infinitely. Mining also has hash difficulty. Mining difficulty is an automatic mechanism that prevents coins from being mined too fast. The computer nodes powering bitcoin can have infinite power so this becomes necessary to limit the collective number of coins mined at any given time.
That said btc is not the only cryptocurrency that is mined. Other cryptos also get generated the same way. Mining can be profitable when one does it using cheap electricity and efficient computing devices. ASICS are the optimal hardware for crypto mining.
As for the power, the math has to be done carefully. Power costs can eat into the profits. Solar energy and other renewable energy may also be explored as a free source of crypto mining electricity.
The first block of btc mined was awarded 50 btc and was mined by its creator Satoshi Nakamoto. He subsequently mined more initial blocks amassing over a million coins before he disappeared from the public limelight. Since block 1 mining difficulty has increased with time. So has the price. When prices are high miners make more than when they are low.
It is btc miners who support the btc network by continously verifying transactions using their computing capabilities and electrical power as the cost. The awarded coins are the returns for the cost incured. The future if money is in bytecode. Computing and electrical power are finally proving to be game-changing inventions that never found perfect use cases until recently. There already exists online marketplaces for computing power.
As cryptocurrency adoption increases, it's becoming clearer that crypto is inevitable. Many people are joining the party and making fortunes before it becomes a saturated market. This has seen a rise in mining computing hardware manufacturing and various mining software for mining being created.