Which authentication process requires only a user ID and password?

Single factor authentication (SFA) is characterized by its reliance on only one form of verification, which typically consists of a user ID and password. This method is straightforward and widely used, as it requires the user to provide only these two pieces of information in order to gain access to a system or account.

In contrast, multi-factor authentication (MFA) enhances security by requiring two or more verification methods, such as something the user knows (a password), something the user has (a token or smartphone), or something the user is (biometric factors like fingerprints). Biometric authentication specifically uses unique physical characteristics of a user, while token-based authentication involves a physical device that generates a one-time password or uses an app for verification.

Thus, SFA is the process that solely involves entering a user ID and password, making it the correct answer for this question.