[yt-users] Profiles and normal graphs

Hi, What's the difference b/t a "density profile" or "temperature profile" etc and just a basic density graph, temperature graph, etc? (Cosmological simulations). Is a profile a graph over a chunk of space which is 2-dimensional plus width-not-too-small /large, whereas a graph is just a 2-dimensional plot, y vs. x, say. Is this chunk what is called a slab, in numerical simulations? And how does a spherically-average profile differ from a chunk or slab profile? Thanks. -R.Soares