Out of the blue, My Applications folder on the storage management has been showing an extreme number of used Gb for which I cannot locate using finder. I was, at first, under the impression that it was an IOS backup until realizing there is a separate section labeled for the iPhone Backup folders. I am unfamiliar with the organization of MacBook's files setup and I am also unsure of how to go about finding the true contents in my disk.
Here is what I am basing my concerns off of:

My applicants folder has around 7GB when combined, however, I have read that what is being shown above is an unreliable source. If this is so, what is a better route I can take in order to check my Macbook's true storage? Why would this application be so far off from what finder is telling me?
Thanks! :)