An OTP, or One-Time Password, is a unique code generated for a single use, typically for authentication purposes. It enhances security by ensuring that even if someone intercepts the code, it cannot be reused. OTPs are commonly sent via SMS, email, or generated by authentication apps. These passwords are often used in two-factor authentication (2FA) systems, adding an extra layer of protection to online accounts. When logging in, users enter their regular password and then the OTP, confirming their identity. This method helps prevent unauthorized access, making it a popular choice for securing sensitive information.