pixel fillrate
The number of pixels the card can render to the screen every second. Before pixel shader processing became the more limiting factor, this was the most accurate measure of performance (along with texel fill rate).
texture fillrate
The number of textured pixels the card can render to the screen every second. To render a 3D scene, textures are mapped over the top of polygon meshes. This is called texture mapping and is accomplished by texture mapping units (TMUs) on the videocard. Texture fill rate is a measure of the speed with which a particular card can perform texture mapping.
source:http://www.gpureview.com/