The difficulty is the degree of difficulty in a blockchain network to find a new block. More miners in a blockchain network mean, higher total computing power in a network. So that now by the increase of the computing power in the network, not more blocks in a shorter time can be found, the blockchain protocol automatically adjusts the difficulty. This ensures, for example, that in the Bitcoin blockchain, a block is “found” every 10 minutes, and not, for example, in 3 or 6 minutes. Since with the Bitcoin network, every 2016th block or every two weeks, the Difficulty is adjusted, one could briefly, if the computational power changes, you could make more profit from mining. However, since the Difficulty in the blockchain network is variable, it is adjusted depending on the period set, according to the computing power in the entire network.