Is there Any one who can tell me what is .dll file in Microsoft Windows . And how do we build it and why

Answer 1

It's called a dynamic-link library, and is basically a shared library.

https://en.wikipedia.org/wiki/Dynamic-link_library

Dynamic-link library (or DLL) is Microsoft's implementation of the shared library concept in the Microsoft Windows and OS/2 operating systems. These libraries usually have the file extension DLL, OCX (for libraries containing ActiveX controls), or DRV (for legacy system drivers). The file formats for DLLs are the same as for Windows EXE files – that is, Portable Executable (PE) for 32-bit and 64-bit Windows, and New Executable (NE) for 16-bit Windows. As with EXEs, DLLs can contain code, data, and resources, in any combination.

Data files with the same file format as a DLL, but with different file extensions and possibly containing only resource sections, can be called resource DLLs. Examples of such DLLs include icon libraries, sometimes having the extension ICL, and font files, having the extensions FON and FOT.[1]

Answer 2

If you want to know more,

try windows programming with C++

https://www.sololearn.com/discuss/459844/?ref=app

Answer 3

Because most programs are dependent upon some external library for their functionality.

Answer 4

Static (vs dynamic) linking can produce huge binaries, because static linking rolls the library code into one executable. Excess statically-linked library code (that really everybody could dynamically share) is like including a copy of Chrome 45 in every YouTube video.

This is useful when distributing DVDs for offline viewing, for an antivirus that MUST have clean binaries, or when you need to run a tool but can't just install all the devtools...

...but it's terrible for any interactive mode (those poor dialup users!) and security updates that affect library code (I have to download 5GB for a 15KB patch?!, or Chrome 46), and ... etc

Answer 5

but why most of the programs can't run without using it.