what are strips?

What are strips? Triangle strips? Quad strips? What are those and why are they saying its faster and how would you make a triangle strip?

With strips you don’t need to send as many vertices through the pipeline becuase you don’t need to send as many duplicate vertices. For instance if you were going to render a quad with GL_TRIANGLES, you’d need to send data for 6 vertices, 3 vertices for each triangle. For a strip, you’d only need to send data for 4 vertices. For instance, if we number the vertices at the corner of the quad 1-4, you can just send vertices 1,2,3,4 for a triangle strip. It takes vertices (1,2,3) for one face then (3,2,4) for the next face. Each additional vertex will take the 2 vertices before it for creating a new triangle. The order of the 2 previous verts alternates in order to preserve the winding order. So if you had 5 vertices in a strip the resulting triangles would basically be (1,2,3),(3,2,4),(3,4,5).

The same basic principles hold true for Quad strips as well. The ordering of the vertices is a bit different in that case, though.

This is a site (french site) where u can find what you need
(you can find it also in opengl books)