A centralised cryptocurrency is managed and maintained by a single entity or organisation, such as a central bank. Centralised cryptocurrencies are subject to government regulations and policies, and their issuance and value can be impacted by these regulations.
Decentralised cryptocurrencies, on the other hand, do not have a single entity controlling them. Instead, they are controlled by a distributed network of computers. Transactions are verified by this network, and new blocks of transactions are added to the blockchain ledger in a secure and immutable manner. They are typically regulated by an open-source protocol rather than a centralised authority, making them difficult to censor or control.