This is not a good or useful question. Please see my comment. Besides, you should understand that the questions of the type "what is the difference between {0} and {1}" are incorrect. If you did not get it, please tell us the difference between apple and Apple.
Please see this discussion:
How to ask a good question?[
^].
See also my answer to this question and my past answer here:
what is the difference between the class and encapsulation in programming[
^].
This is not the we to get any real knowledge. I don't know you background, but you could start here:
http://www.asp.net/get-started[
^],
http://www.asp.net/web-forms/tutorials/aspnet-ajax/understanding-asp-net-ajax-web-services[
^].
You can always get an idea of the purpose of the file patterns if you Google. First two are related to ASP.NET custom controls and pages and the last two — to Web services. You should understand that file names do not really matter, as the services can be configured to use any other ones.
—SA
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