Yes - you can get 'Flat Black' - Black with no metallic pigment in it.
"Metallic" refers to the addition of a metal pigment (usually tiny flakes or spheres) to the paint. As the paint drys (Solvents flash (evaporate) off), the metallic flakes rise to the surface and form a pattern a bit like a tiled roof. The resulting finish is that slight 'sparkly' effect that you see on 'metallic' paint.
Matallics can be hard match if your doing a repair, because the perceived colour depends on how you lay down the last layer of paint with the spray gun - a horizontal pass can give a different effect from a vertical pass. Skilled paint sprayers know this and behave accordingly when doing parts which are to match up.
One good thing about metallics, is that when the tiled roof of metal pigments form, they generally tend to do a very good job of 'covering' - i.e. you can't see through the paint to the primer. The ability to see through the paint is called 'opacity' - next time you see an Imola Yellow Audit S3 - check the match between Bumper and Bonnet and try not to laugh. Yellow is notoriously opaque - the colour of the primer is critical in achieving the correct final perceived colour.
Sorry - I've spent to much of my life being involved with paint!
Here come da judge...