What are the acceptance criteria? Can you give an example?

Acceptance criteria are a set of conditions that must be met for the customer or end user to recognize the work as completed and accept the product. They help determine that the functionality is implemented correctly and meets the requirements.

An example of acceptance criteria for a user registration function:

• The user can successfully register by providing a valid email and password.
• A confirmation email is sent to the specified email after registration.
• When incorrect data is entered, the system displays a clear error message.

Such criteria are usually formulated in the "Given-When-Then" (BDD) format or simply as clear requirements that can be verified.