Web server and Internet Information Server (IIS)

Introduction

When request come from client to the server a lot of operation is performed before sending response to the client. This is all about how IIS and Web server Process the request.

Internet Information Server

IIS (Internet Information Server) is one of the most powerful web servers from Microsoft that is used to host your ASP.NET Web application. IIS has it's own ASP.NET Process Engine  to handle the ASP.NET request. So, when a request comes from client to server, IIS takes that request and  process it and send response back to clients.

Web Server

When we run our asp.net web application in visual studio IDE (Integrated development environment), Visual studio Integrated ASP.NET Engine is responsible to execute all kind of asp.net requests and responses. 

The process name is WebDev.WebServer.Exe which actually take care of all request and response of an web application which is running from Visual Studio IDE.
Web Server is needed when we want to host the application on a centralized location and wanted to access it from many locations. Web server is responsible for handle all the requests that are coming from clients, process them and provide the responses.