What does 'Concurrency Support' mean?

Many programs feature concurrency, allowing multiple users to work on the same record simultaneously. Concurrency control, on the other hand, is the technique through which the outcome of a record's update/delete operation is determined when many users are working on the same record at the same time. Concurrency refers to an algorithm's or program's capacity to perform multiple tasks at once. The notion is similar to parallel processing, except instead of doing the same job, multiple independent processes might execute different things at the same time.