append only event logs - WebOfTrust/WOT-terms GitHub Wiki

Definition

Append-only is a property of computer data storage such that new data can be appended to the storage, but where existing data is immutable.

A blockchain is an example of an append-only log. The events can be transactions. Bitcoin is a well-known Append only log where the events are totally ordered and signed transfers of control over unspent transaction output.

More on Wikipedia