"Exempt" employees are those who meet the strict requirements under the fed FLSA and state law so that overtime pay isn't required (i.e., "exempt" employees may be required to work any number of hours each week with no overtime pay).
To qualify as exempt, an employee must ordinarily (1) be paid a salary and (2) meet a "duties" test. Generally, under fed law, exempt employees must either (a) have a professional license/credential, (b) supervise at least 2 other full-time employees, or (c) have the discretion to make up important company policies.
MANY companies erroneously call employees "exempt" merely because they're paid a salary or are called "managers." But, all requirements must be met, AND MANY companies get the rules wrong.
For example, in the last month, both US Bank (in 17 states) and Albertson's grocery store (in 25 states) both settled big lawsuits because they erroneously treated some non-exempt employees as exempt. The bank will pay out $3.8 million, and Albertson's will pay out $38 million. That's right, MILLIONS of dollars are being paid out by companies because they blow the exemption rules.
So, who is exempt in your company and who isn't? That is the million dollar question, and it's not easy to get a precise answer.
But, simply getting paid a salary doesn't make you exempt. Non-exempt salaried people are entitled to overtime after 40 hours in a week.