Image/Buffer Objects : Which is fastest? When?

Hi,

I have some question about execution time of different memory objects .

  • Which among image or buffer objects is fastest ?
  • In which case/use ?
  • And why ?

Is the following sentence right/wrong :
-> I have an image, I use an image object (and vis versa for buffer )
-> In some cases, image should be buffer object for faster execution . (and vis versa)

Thanks !