Istunnonvarasto

Istunnonvarasto, often translated as session storage, is a web storage mechanism that allows websites to store data on a user's browser. This data persists for the duration of a single browsing session. When the user closes the browser tab or window, all data stored in session storage is automatically deleted. This makes it distinct from local storage, which retains data indefinitely.

The primary use of session storage is to maintain user-specific information across multiple page requests within the same browser session. Examples include remembering a user's login state, shopping cart contents before checkout, or form input that hasn't been submitted yet. It's a client-side storage solution, meaning the data is stored on the user's computer and is not sent to the server with every HTTP request, unlike cookies.

Web developers can access and manipulate session storage using JavaScript. The typical methods include setItem(key, value) to store data, getItem(key) to retrieve data, removeItem(key) to delete specific data, and clear() to remove all stored data for the current origin. The data is stored as key-value pairs, where both keys and values are strings.

Session storage is considered more secure than cookies for sensitive information because it's not automatically sent to the server. However, it's still client-side and thus vulnerable to cross-site scripting (XSS) attacks if not implemented carefully. It has a storage limit, typically around 5MB per origin, which is generally sufficient for session-related data.