Can anyone please explain me what is a NativePixMap…what is the difference/relation between pBufffer and pixmap?
EGL pixmaps encapsulate drawing surfaces of a platform-specific drawing API (such as GDI on Windows). EGLNativePixmapType is the type that represents this platform-specific drawing surface.
If pixmaps are supported, you can create a surface with this native drawing API, encapsulate it as an EGL pixmap, and render to it using EGL client APIs such as OpenGL ES and OpenVG. Support for EGL pixmaps is rare, though.
A pbuffer is a platform independent off-screen surface that is only accessible using EGL client APIs. Pbuffers, when created with the right EGL config, may be bound as OpenGL textures. Thus they are useful for render-to-texture effects. They are also useful when you want to render an image that is larger than the screen, since this is not possible with an EGLWindowSurface.