Logged By Dimension - All users

Hello everyone,

Sorry if the question was already answered elsewhere.
I have an interrogation about the data obtained through the Logged By dimension in Eazy BI reports :
I don’t understand what data is exactly composing the dataset.
In my case, it gets me about 700 users which is neither, the number of users that logged time in JIRA overtime (as the report shows me users without logged time) or the number of active users in JIRA as I have more than 800.
Could someone enlighten me?

Thanks in advance !