Purpose of the checkbox: “show data for current values” available while creating Dashboard report?

What is the purpose of the checkbox: “show data for current values” available while creating a Dashboard report?

Brief Description:

There is an optional field “show data for current values” that we can see while creating a Dashboard report, but it does not say why we must select this option, so sometimes users were confused about whether to select this option or not.

Role: Admin user.

Why is this checkbox/option needed?

Let us take an example user A completed the course on 1st Jan at that time he was reporting to B.
But now A is reporting to C.

Here if we do not check the option the report will show the old data, which means that data that was there at the time of the event trigger.
But if we check the option, it will show the current data for all the records (if anything has changed since)