Concepts

ASP.NET :

ASP.NET is a Web Application framework developed by Microsoft for developing Web Applications. 

It is a successor of Microsoft's Classic ASP (Active Server Pages).

First version ASP.NET 1.0 was released in January 2002 and many versions came after that till version 4.6

ASP.NET Core released in June 2016  is the successor of ASP.NET and it is a free framework and platform independent which works on Windows, MAC and Linux. Since ASP.NET Core has significant changes compared to previous versions it can be considered as Next Generation of ASP.NET.

Visual Studio :

Visual Studio is Microsoft's Integrated Development Environment (IDE) for developing Applications. It contains developer tools and services for creating Applications. It has good code editor with intellisense.

C# :

C# is an Object Oriented Programming Language by Microsoft developed during development of .NET Framework. It is a successor of C++ and the concept was to develop C like Object Oriented Language (COOL) which then named C#. It has OOPs features of JAVA also.

MS SQL Server :

MS Sql Server is a Relational Database Management System by Microsoft which was released in 1989. Whereas its competitor Oracle is the first RDBMS released in 1979.

HTML :
HTML stands for Hypertext Markup Language is a markup language for creating web pages.
Tim Berners Lee invented www (World WideWeb) in 1989 and he invented HTML in 1991.
Web browsers can read HTML files and render to the end user as Web pages.

Webservice :

Webservice is a software designed to provide services over a network. It is used by another Application and not by end users. It can be considered as Web Application components.

It can be used to create Reusable Application components and it can be used for 
exchanging data between different Applications in different platforms. Interoperability 
is the biggest advantage of webservices. Any Application regardless of the programming 
language can have a webservice component and any other kind of Application can 
consume and use it. For eg. a webservice created in JAVA can be used in .NET.

Webservice uses xml to encode and decode data and SOAP (Simple Object Access Protocol)

for transferring the data using open protocols. Webservice Definition Language abbreviated 
as WSDL is an xml based interface definition language for describing a webservice. 
It defines all the functions, its parameters and returning datatypes of a webservice.

UDDI(Universal,Description,Discovery and Integration) is an XML-based standard for describing, publishing, and finding web services.

It includes a registry by which businesses worldwide can register their services on the internet. It uses WSDL to describe the inerfaces of webservices.

AJAX :

AJAX stands for Asynchronous Javascript And XML. It is a web technology that works on

client side to create asynchronous web applications. Its great advantage is it avoids page 
reloading there by providing better and faster user experience for the website visitors. It 
make use of Javascript and XMLHttpRequest object for exchanging data asynchronously
between browser and server. For dynamic display DOM is accessed with Javascript. It can
be considered as a web technology that lets Javascript communicate with a web server.