Pretend, for a moment, that someone has just made a claim, and you are trying to decide whether or not that claim is true. How do you go about evalutating their assertion? How do you decide if that person is right or wrong? How do you know the truth?
Epistemology is the study of how we know what we know. It is the area of philosophy which attempts to create methodologies for discerning truth from falsehood. So, for example, if I were to claim, “I am wearing a green shirt,” how could you verify or disconfirm my statement? Well, if you’re in the room with me, you could simply look at my shirt. However, what if you’re not in the room with me? You might place a phone call to someone who IS with me, and ask them– but how would you know that this new person was telling the truth, and not lying?