A Gettier problem is a philosophical issue that challenges the traditional definition of knowledge as justified true belief. According to this definition, for someone to know something, three conditions must be met: the belief must be true, the person must believe it, and there must be justification for that belief. However, Edmund Gettier, who introduced these problems in 1963, presented scenarios where these conditions are satisfied, yet intuitively, the person does not truly "know" the information. In a classic Gettier scenario, a person might have a justified belief that their friend is in the office because they see their car parked outside. However, the friend is actually not in the office; instead, someone else has parked the same car there. This situation shows that even with justification and a true belief, knowledge can still be absent, prompting philosophers to reconsider the nature of knowledge itself.