DOM Storage
DOM Storage is a web browser API that allows web applications to store key-value pairs locally in the user's browser, providing persistent data storage beyond a single session. It includes two mechanisms: localStorage for long-term storage that persists across browser sessions, and sessionStorage for temporary storage that lasts only for the duration of a page session. This technology enables web apps to save user preferences, cache data, and maintain state without relying on server-side storage or cookies.
Developers should learn DOM Storage when building client-side web applications that need to store data locally for improved performance, offline functionality, or user experience customization. It is particularly useful for saving user settings, caching API responses to reduce server load, and implementing features like shopping carts or form autosave in single-page applications. Unlike cookies, DOM Storage offers larger storage capacity (typically 5-10 MB per origin) and avoids sending data with every HTTP request.