36. What are the differences between cookie, local storage and session storage?

Here’s a comparison of cookie, local storage, and session storage in terms of their purpose, size limits, lifespan, and example usage:

Example Code

1. Cookie Example
   Set a cookie:

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document.cookie = "username=John; expires=Fri, 31 Dec 2025 23:59:59 GMT; path=/";

Read a cookie:

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console.log(document.cookie);

2. Local Storage Example
   Set data in local storage:

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localStorage.setItem('theme', 'dark');

Get data from local storage:

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const theme = localStorage.getItem('theme');
console.log(theme); // Output: dark

3. Session Storage Example
   Set data in session storage:

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sessionStorage.setItem('token', 'abcd1234');

Get data from session storage:

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const token = sessionStorage.getItem('token');
console.log(token); // Output: abcd1234

Key Differences:

• Cookies are sent to the server with every request, increasing network traffic.
• Local storage and session storage are purely client-side, reducing server load.
• Local storage persists data until manually cleared, while session storage is cleared when the tab or window is closed.