What Is a Passkey and How Does Passwordless Login Work?

A simple explanation of what passkeys are and how passwordless login works using public and private key cryptography. We explain why the server never sees your private key, how domain binding protects against phishing, and why fake websites have almost no chance. We also cover how passkeys differ from passwords, what login with biometrics or a PIN looks like in practice, and whether password managers are still needed in a passwordless world.