localStorage and SessionStorage

When it comes to store or persist data on the client side, the only option available before HTML5 was cookies.

While cookie is a good option to store data on the client side, it has a limited capacity of only 4kb. Also, issue with cookies is they get sent to server with every request thus adding extra load to each request. Since anyone can add a cookie to the browser, its not very secured, a cookie added manually or by some ill-intended automation code may actually appear to be to be coming from a valid user session to the server.

With HtML5, there are two new options to store data on the client side - localStorage and sessionStorage

StorageType	Size Limit	Expiration Period	Readable on
Cookies	4KB	set by the code when creating the cookie	any window
LocalStorage	10MB	Never (until user clears out)	any window
SessionStorage	5MB	On Tab close	only the tab where its ceated