Asp.net is technology which allow user to create dynamic web application/websites.
Ajax helps in asynchronous communication with server. Ajax toolkit is free feature
provided by Microsoft. From official website of asp.net you can download and configure with your visual studio and start working with Ajax controls.this very much interactive and easy to use. Most developer worried about the name Ajax But it is so simple. All the controls with in the toolkit are so good. You can find that how to use the particular control, help from
asp.net.