gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
....
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);

glDrawElements

Primitive Processing - Vertex Shader - Primitive Assembly - Rasterizer -
Fragment Shader - Depth Stencil - Color Buffer Blend - Frame Buffer