DLT (Distributed ledger Technology) is one of the very core features which allows blockchain the ability to be a trustless and secure system.
A ledger is a permanent summary of all amounts entered in supporting journals which list individual transactions by date.
Without DLT, blockchain would just be a timestamped, hashed database. DLT creates the possibility to spread and proof check data amongst many other computers, with no one computer as the “main” or “master” computer. Essentially it’s a vote, if the majority or 51% vote yes to the data being correct, then the data is considered correct and not fraudulent and they agree on a shared state of data.
Proof-of-work DLT: A decentralized network of multiple computers without one computer being in charge or the main computer. Computers in a decentralised distributed network communicate facts between them, with the example of accounts, Mary has 3 coins, the other computers will use a consensus to come to an agreement that Mary has 3 coins. If 51% or more agree on it, the data is processed and we can safely know that Mary has 3 coins.