Homogeneity is the sameness of things. If you're looking for homogeneity in your wardrobe, you'll want shirts and jeans that all have something similar about them.
Homogeneity can also mean that something is the same throughout. Plain yogurt has a homogeneity about it — it's white all the way through and it should be the same texture throughout. On the other hand, yogurt with fruit at the bottom can be described as having heterogeneity — different textures and different colors. The Greek root homo-, means "same," and genos means "race" or "kind" — so homogeneity is the quality of being "the same kind."