Mining difficulty usually refers to the measurement of how hard and time-consuming it is to solve the complex cryptographic puzzle that is required to create new blocks for any given cryptocurrency. Blocks contain transaction data, and mining is necessary to run the network and mint new coins. A high mining difficulty means that mining the next block requires high computing power from competing miners.
Mining difficulty is a mode that all cryptocurrencies use to ensure that a constant, stable timestamp is maintained between the creation of blocks on a particular cryptocurrency blockchain. As a result, the level of difficulty is not the same at all times and it is largely dependent on the number of miners currently available on the network.
A larger pool of competing miners automatically leads to an increased mining difficulty while a lower concentration of competing miners will lead to a decreased mining difficulty. The idea is to maintain the time between a block and the next.
To quickly hash the mining difficulty, miners usually form mining networks where they combine the powers of their systems to quickly solve the cryptographic puzzle and then share the rewards that accrue.
Mining difficulty is also an important way to protect the blockchain from hackers and all forms of malicious attacks.