Where can I find an official explanation of the building blocks of pega application URL?

If I access my local pega instance using the URL http://localhost:8080/pprweb, the login page is displayed with the URL http://localhost:8080/prweb/beEBp4uRVTogorRwSwWqbOtn9IL2fwdI*/!STANDARD

Then after login, the URL will change to

http://localhost:8080/prweb/0UEDwA8Fx5dCTJq5XY-K4DpS6vVc7jaN*/!STANDARD?pzPostData=749318337

I remember that the encoded part (bold chars) of the URL is the hash value of the current Access group, but I couldn't find any official document that backs up my understanding.

Before, there was an online academy course explains the building block of pega application URL, but I couldn't find it anymore.

***Edited by Moderator Marissa to update platform capability tags****