Magic links are a type of passwordless login that allow users to log into an account by clicking a link emailed to them, rather than typing in their username and password. They work by generating a unique token and sending it via email, which the user must click on to access the account. Magic links have several benefits, including easy user experience, reduced infrastructure maintenance, zero password breaches, fewer customer support requests, fast and simple onboarding, and not relying on specific hardware. However, they also have some drawbacks, such as email deliverability issues, potential spam issues, security concerns tied to email, limited administrator visibility, and the need for one-time use links, multi-factor authentication, expiration dates, and simple emails with relevant subject lines and "From" names. When implementing magic link authentication, it's essential to choose an email service provider that prioritizes speed, reliability, and support for necessary protocols and standards. Additionally, integrating a magic link flow into an app requires generating and saving the unique token, generating a link using that token, and authenticating the user at the magic link endpoint.