When, so when it was foggy, would you turn on the fog lights or the main beams?

some cars don't even have fog lights so i can see where the confusion would come from

High beams are only to be used at night when there is absolutely no public lights and you have to use your regular lights when you're crossing another driver or are passing through a living area. Fog lights are to be used when it's foggy, rainy or snowy. They're not meant to brighten everything, it's just meant for the other drivers to be able to see your lights when the visibility is poor

I thought they were just different names for the same thing... now I know better haha

Fog lights are a deep yellow wavelength which cuts through the fog better so you are more visible (as mikriarktos said). Using high beams in fog rarely helps the driver anyway.

Using high beams in fog is generally a very bad thing. The fog dispersed the intense light and will blog other drivers and can make it harder for YOU to see. Real fog lights are generally yellow as beast says, and aimed appropriately. To add to the confusion- cars often have “driving lights” “road lights” or other terms used for a set of lights which is not your headlight high or low beams and point forwards to aid in seeing the road and being seen. These are often found in the lower bumper of the car. The term “fog light” can also refer to a front or rear mounted light which isn’t for seeing in the fog, but points upwards to mark your location and make your car more easily seen by others.

So not all yellow lights are fog lights, as beast says they are designed a certain way and should be on a certain wavelength of yellow. The internal structure of the light and the lens characteristics help determine the pattern and behavior of the light it emits. This is why you can’t just throw any old bulb that fits into a light housing, or add components such as many popular “HID” “Projector” or “LED” conversions for automotive lights. The housing is one of the major factors on light, but the housing and bulb need to be designed to work together or else you can be a danger to yourself or others.