Which of the following best describes window.localStorage?

• A. stores data with no expiration date
• B. stores data for one session (data is lost when the browser tab is closed)
• C. runs JavaScript in the background, without affecting the performance of the page
• D. defines a bi-directional override

Answer: (A)

localStorage is a persistent client-side storage for key-value pairs, with no expiration date. Items you store remain available even after the browser is closed and reopened, until you explicitly remove them or the browser clears its data. This makes it different from sessionStorage, which keeps data only for the current browser session and loses it when you close the tab or browser. localStorage operates within the same origin (same domain, protocol, and port), is accessed synchronously via JavaScript (methods like setItem, getItem, removeItem, and clear), and has a typical per-origin size limit that varies by browser. It doesn’t run code in the background or provide any override functionality; it’s simply a storage mechanism.