Bitcoin is heavily dependent on this mining process. Because with mining done by miners Bitcoin (miner) will validate every transaction, build and store the new block into blockchain. To save the new blocks into the Blockchain, miners must reach consensus.
Role And Function Of Miners
Bitcoin Mining is actually a mine activity using a particular device. The process through solving a series of mathematical problems (puzzles) based on certain difficulty levels. Well this activity is called "Mining" or cool term is "Bitcoin Mining".

So clearly, that if someone is mining Bitcoin, that means the person is using a mining device. Can use CPU, GPU, FPGA, and ASIC. An explanation of this device will be discussed in the next section.

Mining actors, referred to by the term "miners", or the cool language is "Miner". Well, sometimes, we also still leave the question, what exactly is this miner Bitcoin doing?Let's discuss it. Bitcoin mining process is similar to mining of precious metals such as gold. It's just the difference, if Bitcoin mining is done digitally to solve the puzzle, and gold mining through the process of gold mining.
Being similar, because sometimes there are miners who feel loss, because it can not and difficult to find gold, and some are successful. However, the real picture is, there will be many difficulties when doing the mining process.
Likewise with Bitcoin mining. There are a series of difficulties and challenges faced. As for being a miner, then we must be connected into the Bitcoin network. Once connected, then we will be a "node". The term node describes all devices connected to the Bitcoin network.
So what are the miners doing? When someone connects to a Bitcoin network using a device, the node will perform a series of tasks. The tasks performed are:
All nodes that are connected in the Bitcoin network must listen to all transactions that occur. Followed by validating the audited transaction. By checking the digital signature. It is related to the truth of digital signatures and the output included in the transaction must be completely un-spent (not yet issued in other transactions-ensuring no double spending).

Keep Blockchain and listen to the new block created.
A miner, actually serves to keep the blockchain. Related to handling all transactions that occur. Miners too, will retain Blockchain which has kept all transactions. Miner, can request all history of the block to another node that has entered before it entered into the network. Listen to new blocks that are broadcasted within the network, then validate the received blocks. Because in the block there is a series of transactions, then every transaction that is in the block and even then also must be validated, and valid. Create a new block candidate
Once we have a full copy of the block chain (blockchain), then we can start building blocks. To do so, by grouping all the transactions we hear into the new block, which can later expand on the block we know. However, we must also ensure that all transactions within the block are valid.
Finding Nonce to be a valid block
After we validate all transactions on the candidate block, then is looking for nonce in order to make the block become valid. The step here is the most difficult step faced by miners.