A banking application requires users to enter a 4-digit PIN for login. Explain how you would test this input field to ensure that it accepts only…

A banking application requires users to enter a 4-digit PIN for login.

• Explain how you would test this input field to ensure that it accepts only valid 4-digit numbers and rejects invalid inputs.
• Mention a few test cases you would include and explain why such testing is important for system security and reliability.