Bitcoin miners are a specific type of computing device with specialised architecture geared up to solving complex mathematical problems.
Bitcoin is a digital asset of which when transacted between devices, the transactions are verified by the miners. Bitcoin runs on a decentralised network and the transactions are tracked on a distributed ledger.
Each bitcoin transaction that takes place is added into a group of transactions called an individual block, which is a group of transactions. Each block has an associated ‘proof of work’ attached to it which is a complex mathematical hash. A new block of transactions is added to the network every 10 minutes and the “Difficulty” rating adjusts to ensure the 10-minute interval is maintained on every new block.
Bitcoin miners add the individual blocks to the block chain or distributed ledger by solving the complex mathematical hash and the first one to- do so is rewarded in bitcoin.
To have more chance of winning the race to solve the hash, miners can join up with other miners to add additional compute, these are called mining pools that can contain tens of thousands of bitcoin miners. In this situation any rewarded bitcoin is shared out proportionately to each bitcoin miner within the pool based on their contribution of compute.