What is OpenGL ES: A definition and scope

The scope and definition is stated here from the Khronos group

OpenGL� ES is a royalty-free, cross-platform API for full-function 2D and 3D graphics on embedded systems - including consoles, phones, appliances and vehicles. It consists of well-defined subsets of desktop OpenGL, creating a flexible and powerful low-level interface between software and graphics acceleration. OpenGL ES includes profiles for floating-point and fixed-point systems and the EGL? specification for portably binding to native windowing systems. OpenGL ES 1.X is for fixed function hardware and offers acceleration, image quality and performance. OpenGL ES 2.X enables full programmable 3D graphics

ES 1.1 for fixed function hardware. This is the traditional OpenGL where the GPU does not offer programmability

ES stands for embedded systems like cell phones

"C" like programs written in a language called GLSL (GL Shading Language) are compiled, linked, and run on the GPU to provide more flexible options for geometry, raster, and fragment rendering. This version is not backward compatible with 1.1, so called the fixed function graphics pipeline.