A single point of failure (SPOF) in the context of password managers refers to a situation where a single security measure is compromised, leading to the loss of (or unauthorized access to) all your stored passwords. For example, if your master password is compromised or forgotten, it could potentially lock you out of your password manager or expose all your credentials. Effective password managers provide additional security measures like multi-factor authentication (MFA), recovery options, and emergency access to mitigate this risk.