In the past, if a web page wanted to remember certain pieces of information about a user and be able to recall it upon a subsequent visit, they had several choices. One, the page could write the information to the server in what are known as cookies. One problem with cookies, is some users have their browser setup not to allow cookies. No way around that. Besides, it also requires more network traffic providing more opportunities for a hacker to intercept critical personal information. Second, a page could store the information on the users own computer using local storage. No network calls, just store and retrieve the information directly from the users hard drive.