Can you explain what is meant by reliability in the context of ACID transaction properties?

In the context of ACID transactions, durability means that after a transaction successfully completes, its changes are guaranteed to be saved in the database and will not be lost even in case of system failures, such as power outages or server crashes.

This is achieved through mechanisms like transaction log recording, using durable storage media, and recovery procedures. Thus, if a transaction is committed, its results are permanently saved and available for subsequent operations.

Example: if you transfer money from account A to account B, and the transaction completes successfully, then even if the power suddenly goes out after this transfer, the data about the new balance will be saved and not lost.