I saw some sentences using "on top of" while I was reading some book which was about ASP.NET Core (which is a Microsoft Web Development Framework). the sentences:
1-(MVC) It was created on top of the components for Web Forms.
2- Dot Net Core is built on top of the new dot net core framework.
I have searched for some definitions for "on top of something" and also for knowing that how to use this idiom in a sentence, but actually haven't realized what "on top of" mean here in these two sentences! So would anybody explain it to me please?