On MathSciNet, cookie technology is used to implement the Clipboard feature. This helps the browser remember specific information like what items you have placed in your clipboard and the headlines list you visited last. The cookie we place on your hard drive will time-out after two hours. This means that after this period, our server will have no record of your visit and the items you have placed in the clipboard will no longer be available.
A cookie is information placed on your hard disk so the Website you are visiting can remember something about you at a later time. More technically, it is information for future use that is stored by the server on the client side of a client/server communication. Using the Web's Hypertext Transfer Protocol, each request for a Web page is independent of all other requests. For this reason, the server has no memory of what pages it has sent to a user previously or anything about your previous visits. The cookie helps the server to remember this information thus allowing MathSciNet to store information like citations you place in your clipboard and allowing you to return to the previous headlines list.
You can view the cookies stored on your hard drive (although the content stored in each cookie may not make much sense to you). The location of the cookies depends on the browser and can be found by searching your hard drive. For example, Internet Explorer stores each cookie as a separate file under a Windows subdirectory. Netscape stores all cookies in a single cookies.txt file. Different browsers will store cookies in other locations.