Scanline and raytrace
vray mental ray are raytracers ,mental have both but its designed to work as a raytracer
basically raytracers need to put all in memory thatīs why you have to be very carefully with detail.
Today scanline its the main choise in movies since lots of details are needed (see Avatar).
Mental ray its also used,but for really heavy things Renderman its mostly used,see Cinefex.
For advertising and arch generally raytracers are used since the two main choices(mental and vray) are very easy to setup,no to mention the amount of pre-made assets.