What are the differences between these IBM.Data.DB2 dlls?

I have these dlls installed on my box. What are the differnces between them and when would I use each?

IBM.Data.DB2.dll
IBM.Data.DB2.Entity.dll
IBM.Data.DB2.ASP.dll
IBM.Data.DB2.9.5.5.dll

One other thing, my db2 data is on Z/OS Mainfram开发者_运维知识库e, if that makes a difference.

By "my box" I assume you mean something like a Windows desktop client that you use to connect to your DB2 data source. The article Which DB2 9.5 client connectivity option is right for you? explains (kind of) why you have all those different DLLs installed on your box.

The IBM.Data.DB2.dll file is the main resource reference you would add in Visual Studio to use its various methods. You can add all of those DLLs as references in a dummy Visual Studio project then browse them in the Object Browser, and you will see their different methods or lack of.