Access tokens have become essential in securing online interactions by functioning as digital keys that grant users access to specific resources without needing to re-enter their credentials. Typically formatted as JSON Web Tokens (JWTs), access tokens are crucial within the OAuth 2.0 framework, ensuring that users have the correct permissions while enhancing security through their limited lifespan. Unlike refresh tokens, which have longer lifespans and are used to obtain new access tokens, or ID tokens, which confirm user authentication, access tokens are designed for short-term use to enhance both security and user experience. They allow systems to authenticate requests without burdening the main servers, improving scalability and performance. Implementing best practices, such as using HTTPS and setting short lifespans, can mitigate risks and improve security. Access tokens have simplified authentication and authorization processes, making them a cornerstone of modern web security.