CodeXL User GuideVertex Batch
Vertex Batch: A vertex batch is a group of vertices sent to the graphic driver in a single API call. In OpenGL, this effectively means the number of vertices sent to the graphic pipeline with a single function call. For example, the function glVertex3f always generates a 1-vertex batch, while glDrawElements creates a batch of the size determined by its count parameter value. The number of vertex batches sent to the driver represents the cost of drawing, while the batch size is the benefit of each function call. Drawing 200 1-vertex batches has the same benefit as drawing a single 200-vertex batch, for 200 times the cost. For this reason, it is best to draw as many vertices using as few batches as possible.