Here Mudassar Ahmed Khan has explained with an example, how to set Session variable using jQuery in ASP.Net using C# and VB.Net.
jQuery is a JavaScript library and JavaScript is a Client Side language and hence directly it is not possible to set Session variable in jQuery.
Thus, the solution is to make an AJAX call using jQuery AJAX and pass the value of JavaScript variable to a Web Method and inside the Web Method, the value will be set in Session variable in ASP.Net using C# and VB.Net .