Bitcoin mining is a process needed to avoid double spending attempts (i.e. when somebody tries to spend the same bitcoin more than once), confirm transactions and regulate the emission of new bitcoins.
Since the Bitcoin network is decentralized, no central authority can be in charge of confirming transactions, the process has to be carried out in a decentralized manner.
A system of economic incentives guarantees the security of network, as users are rewarded for good behaviour. The blockchain is maintained by miners, providing computational power (with specific hardware) to verify and successively confirm transactions in exchange for bitcoin – an economic incentive to compensate them for the task performed. Through the mining process, transactions are added to the Bitcoin blockchain. This process is fundamental to confirm to the rest of the network that a transaction has taken place and to avoid malicious attacks to double spend bitcoin.