I think the OP is asking the basic difference between HID and LED headlights. BMW has 3 main types of headlights : 1) Halogen, which is I believe what you are referring to when you said “mostly yellow with big bulbs” 2) HID/xenon which uses a xenon gas bulb as projects a crisp white light, you will see a projector/bubble in the center of the headlight which is where the xenon beam comes out of 3) LED which produces a light similar to xenon but uses less power and has certain other benefits, the headlight itself looks more similar to a halogen headlight except it has an LED bulb instead.
As for the angel eyes, Halogen headlights do not have angel eyes. HID and LED headlights both have LED angel eyes (producing a bright white look) but the shape of the angel eyes is slightly different.
That is my simple explanation
