The judicial branch acts as a check on legislative power by interpreting laws and ensuring they align with principles outlined in a country's constitution. Through the process of judicial review, courts can invalidate legislation that violates constitutional rights or principles. This function safeguards against potential abuses of power by the legislature, protecting minority rights and maintaining the rule of law. By providing legal challenges to legislative actions, the judicial branch enables a system of checks and balances that is essential for a healthy democracy, reinforcing accountability and fairness in governance.