Hi, welcome to the forums.
It might be helpful to read up a bit more on RDMS:
Companies track and store all kinds of information on users. For example, let’s say you subscribe to the NYT and they send you a daily email of article abstracts. You start to read an article and then click on the link to go to the entire article online. Look at the URL. It might look something like this:
That campaign_id, instance_id, segment_id, regi_id and user_id are pulled into a table or tables along with thousands of other user clicks. All that id info is unique to each user that is sent the email. That data is then explored and analyzed and then based on the findings a number of things could happen—they know more about what stories you read, how much time you spend on each story, etc. etc. The NYT uses Google’s Big Query (a cloud-based data warehouse) to compile all this info and data analysts and scientists explore, analyze, run A/B tests, draw conclusions & make predictions from it in order to inform various departments so they can make whatever business decision(s) they need to make. For ex: what was the most popular story in Queens, or, how many users who live in Queens clicked on what stories? What did users who are in this age group gravitate towards? What was the most popular time for traffic on the website? Etc.
This is just one way data is collected and used in a business environment.
I hope that makes sense(?)