PDB:
Debugging symbols are the data that let the debugger show you source and line information, variable names, and data type information for your program. All that information is stored in a .PDB (Program Database) file associated with your modules.
When you debug a Visual Studio .NET application, the debugger first maps the native code to MSIL, and then maps the MSIL code to source code by using a PDB file.
Resx:
There are two types of resource files: Basic text resource file and ResX resource file. A .resX file is an xml version of a resource file. Where the text-based file was used to handle only strings, this file can handle strings and objects. Check out System.Resources namespace.
.disco: -- Microsoft Discovery
disco is a Microsoft defined specification for discovering Web services that are available on a server. There are something called as Static & dynamic discovery .. just google for these terms .. there are numerous articles on them.
Best Regards
Vadivel
MVP ASP/ASP.NET
http://vadivel.thinkingms.com