The biggest difference between feta and goat cheese is what they are made of and their flavor/texture. Feta is a greek cheese made from sheep or sheep and goats milk. It's brined usually in blocks with oil and herbs. It's salty, tangy, and usually a harder consistency than goat cheese. Goat cheese is made with strictly goat's milk. It can be made in a variety of ways, flavors, and consistency, but tends to run softer and smoother than feta. Goat cheese typically has a consistency where you could spread it across toast or crackers. It is also a bit tart in flavor, but usually a bit more subtle. Both sheep and goat milk (therefore cheese) has less lactose in it and is easier for humans to digest. Note: hard goat cheeses do exist of course, but in comparing feta a goat cheese, we are typically talking about soft goat cheese.