The unique feature of the Bitcoin network is a distributed public ledger that records all ownership and transactions of Bitcoin. As transactions take place, the data is grouped into “blocks” and chronologically added to the network’s blockchain - an ongoing linear chain of data blocks.
The blocks that make up the chain are intended to be structurally identical - each block contains a block header and the transaction data. Each new block contains cryptographically verifiable data regarding transactions, as well as a numerical challenge that must be solved in order for the current block to be approved and added to the blockchain.
A high block count shows healthy activity in the chain whereas a low block count shows limited activity in the chain.