A one-time password (OTP SMS) is a text message with a unique code that is used to verify the user's identity or authorize a specific action, such as logging into an account, a financial transaction, or changing a password. The code is automatically generated, has a limited validity period, and is intended for one-time use.
While SMS is one of the most popular methods of delivering one-time passwords due to its speed and availability, OTPs can also be transmitted through other channels such as instant messengers, email, voice messages, or mobile apps. This makes them a versatile means of improving security and protecting information.