For example, it is not uncommon for users visiting an online retail store to change their minds, abandon a list of purchase items, and decide on a completely different set of selections. In such a case it may be expedient to update the Session object by deleting inappropriate values. By using the Contents collection's Remove method, you can selectively remove a reference to a variable that was added for the session state. A browser must request pages from the same Web server for scripts to access session information. Instead, special software distributes all requests for the site URL to whichever server is free, a process called load balancing .
Load balancing makes it difficult to maintain session information on a cluster of Web servers.
To use ASP session management on a load-balanced site, you must ensure that all requests within a user session are directed to the same Web server. If all links in your application pages are relative, future requests for a page will be routed to the same server. ASP creates a new user session on that server. The browser will request the specified page, and all subsequent requests will be routed to the same server as long as specific server names are not referenced in the original URLs. Using Cookies A cookie is a token that the Web server embeds in a user's Web browser to identify the user.