Deno's localStorage API provides a way to store key-value pairs in a web-like environment, similar to the Web Storage API found in browsers. It allows developers to persist data across sessions in a Deno application. This API is particularly useful for applications that require a simple and effective way to store data locally.

Deno's sessionStorage API operates similarly to the localStorage API, but it is intended for storing data temporarily for the duration of a session. Data stored in sessionStorage is cleared when the application session or process ends. This makes it suitable for temporary data that you do not need to persist across user sessions.