Web Storage provides a way for clients to store data

including Localstorage and Sessionstorage. They can only read and write data from the current domain, except that the data stored by Localstorage will not expire, and sessionstorage stored data will be emptied every time the browser is closed.

Ps:

• Many browsers now offer "Anonymous access", "Safe Mode", "stealth window" and so on. In this case, the browser will re-establish a new localstorage, so the pages in these modes are unable to access the data in the normal mode of the page.
• Once, Firefox supports Globalstorage: Localstorage that can read and write data stored in all domains. But globalstorage not become a standard. Firefox was abandoned after 13.0.

Web Storage provides a way for clients to store data