Polygons versus Triangles vs Faces

I seem to be caught in a terminology definition challenge.
I am in the process of creating an iOS game.
Could someone please provide a definition.

http://forums.cgsociety.org/archive/index.php/t-7499.html

 

Unity uses tris, so so should you.

1.Polygons are faces.
2.Tris are 3 sided faces that unity (and i think graphics cards) uses
3.faces are the cause of conecting virticies

Oh someone commented before me

 

In your software you might have a quad, but internally it's always triangles (two in the case of a quad).

If your geometry is clean, with no intersecting and/or co-planar triangles, your quad will always have two triangles, your pentagon will have three, hexagon four, and so on!

Every shape just has to be divided into triangles, otherwise they'd be forced to be co-planar, but luckily they are not!

Think about a flat quad, meaning all vertices are co-planar. You might think it's irrelevant in what way it's divided, but when you move a vertex so it's not co-planar any more, the geometry will be different depending on how it's divided.
The quad can't bend smoothly to accommodate it's surface to all the vertices!!!
So how does the quad stays being a quad if their vertices are not co-planar? It's because there is a hidden edge there... that hidden edge is shared by the two triangles forming the quad. The smooth shading might fool you into thinking the quad is still a quad, the wireframe will show the quad as a quad, but it's actually two triangles!

 

Thanks guys for your excellent responses. I now feel somewhat informed.

I am trying to find the most logical way for Poly Count optimization for Mobile.

Here are my thoughts.
Model all characters and environments for a PC build. (In case I ever want to release to PC/OSX)

Optimize all characters and objects with the new Poly Reduction tool from Atangeo for iOS http://forum.unity3d.com/threads/126251-Polygon-Reduction-Plugin-Preview

Does this seem logical...or am I expecting to much.
What would be your methodology?

 

Automatic tools will always be lower quality than hand-making the low res model.

 

But as a tiny developer you probably don't have time for hand optimisation. Unless you want to develop out of date games that take years to make, you'll want to be taking advantage of every time saving tool you can get.

 

Thanks Hippo, I am a solo Indie....and efficiency is important from both a time and cost perspective.
(Did you also hear from my other biz partner Dr. Robert A about some synth stuff?)

 

Depends what type of object. Any animated object I would definatly optimize by hand at least. If you build your models with good topology optimization isn't that big of a hazzle. Boring sure but pretty quick.