A default password is a pre-configured password set by manufacturers on devices, software, or online accounts before they are sold or distributed. These passwords are typically simple, such as 'admin' or '1234', to make initial setup easier. However, if users do not change these passwords, devices become vulnerable to unauthorized access, as default passwords are widely known and easily found online. Cybercriminals often exploit unchanged default passwords to gain control over systems or steal sensitive information. It is a key cybersecurity best practice to change default passwords immediately after setup to protect against potential attacks.