Complex sentence: Whereas Bitcoin uses a blockchain for its distributed database, Nano's distributed ledger is implemented by way of a data structure representation of the directed acyclic graph (DAG), which combines blocks and transactions such that all parties who send transactions participate in the verification process.
Split into simpler sentences: Whereas Bitcoin uses a blockchain for its distributed database, Nano's distributed ledger is implemented by way of a data structure representation of the directed acyclic graph (DAG). In cryptocurrencies, a DAG structure is one which combines blocks and transactions such that all parties who send transactions participate in the verification process.