The course logs record every time a student performs an "action" -- logs in, opens the course, opens a quiz, submits an answer, submits a quiz for grading.
If you ever need to find out when a student has logged in or to track a student's activities, you can search the logs.
Find the Logs
After logging into your section of Newsroom 101, click on Reports, then Logs.
In the most common use, pull down the "Participants" box and choose the name of a student you want to check on.
You can download the logs into a spreadsheet if that would help you. The logs tend to be quite long, because they record so many actions for so many students.