What is metadata in .NET?

Question

I googled several sites to understand what metadata is in .NET and it means.

I\'m still new to C# WPF desktop application programming. Back when I was

Answer 1

Since others already provided great explanatory answers, I'll just mention how you can view metadata yourself.

In your Microsoft SDK directory (most likely variations of C:\Program Files\Microsoft SDKs\Windows\v7.0A\Bin\NETFX 4.0 Tools) there's program called ildasm.exe - it's simple disassembler that allows you to view compiled .NET binaries.

You can build very simple console application and use ildasm.exe to view compiled contents. View/MetaInfo/Show! command (or simply Ctrl + M) will display metadata - you can check how they look like. Part of metadata from application printing Hello to console:

TypeDef #1 (02000002)
-------------------------------------------------------
TypDefName: Program  (02000002)
Flags     : [Public] [AutoLayout] [Class] [AnsiClass] [BeforeFieldInit](00100001)
Extends   : 01000001 [TypeRef] System.Object
Method #1 (06000001) [ENTRYPOINT]
-------------------------------------------------------
    MethodName: Main (06000001)
    Flags     : [Public] [Static] [HideBySig] [ReuseSlot]  (00000096)
    RVA       : 0x00002050
    ImplFlags : [IL] [Managed]  (00000000)
    CallCnvntn: [DEFAULT]
    ReturnType: Void
    1 Arguments
        Argument #1:  SZArray String
    1 Parameters
        (1) ParamToken : (08000001) Name : args flags: [none] (00000000)

Here you can see type definition (Program) and one of its methods (Main), which takes single input argument and returns void. This is naturally only part of metadata, even for simpliest programs there's a lot more.