Final answer:
The ADEA protects employees aged 40 and older from age discrimination, with exceptions for essential job qualifications and incentivized early retirements.
Step-by-step explanation:
The Age Discrimination in Employment Act (ADEA) prohibits discrimination in the workplace against employees who are 40 years of age or older. Two known exceptions for regular employees pertain to bona fide occupational qualifications, where age is essential to the job, and situations where age limits are set based on workforce reductions where older workers are offered benefits to incentivize early retirement.