"In England, they do not eat soup; they drink it."
Translation:En Angleterre, on ne mange pas la soupe, on la boit.
"they" here is being used to vaguely to refer to people in a general sense, some unspecified people that are representative of the populace as a whole. Grammarians sometimes refer to this as the "fifth person". As another example, if I were to say "In Italy, you can get pizza from a vending machine" (which you can, by the way), am I saying specifically you can get such a pizza, excluding everyone else? Or do I mean more generally that "pizza from vending machines is available for purchase in Italy"?
In English we can use pronouns in this weird, vaguely general way - in fact, I've done so multiple times already in this post. ("Which you can, by the way", "In English we can use...") But we also have a much less common pronoun reserved specifically for this purpose: "one", as in "In England, one does not eat soup" or "In Italy, one can get pizza from a vending machine". This is the way the French do it: if you want to refer to vague, generic people, you use the vague, generic pronoun: on.
See Arcaeca's brilliant explanation above. If that somehow doesn't satisfy you, then have a read of this: https://www.frenchtoday.com/blog/french-grammar/understanding-french-on-subject-pronoun
In case you are curious about the historical differences between "soupe" and "potage," here you go!"
Soupe is the older term and dates to the Middle Ages. It refers to the meats, vegetables and gravy broth that were served on une tranche de pain (French) or on a trencher (English).
Toward the end of the Middle ages, the rising bourgeois considered the dish too "rustic" and in lieu of soupes, potages, typically made from vegetables, were cooked down in a pot until the consistency was smooth. This was served either hot or cold in a bowl rather than on bread.
Today the line between what is considered a potage and what is considered a soupe is a bit murky in French, generally something made from a meat broth with chunks of things in it is a "soupe" and a smooth blended dish from a water base usually made of vegetables is a potage...but from what I have seen in French grocery stores that isn't necessarily the case. The words do seem to be used interchangeably.
This may be similar to the use of stew or soup in English- the terms are a bit subjective. However, I'll leave it up to a native speaker to make the call as far as potage/soupe.
The generic and category name is still "une/de la soupe". There is an endless list of possible recipes and ingredients, but nowadays, there is no meat in soup. Yet, you can have pasta, rice, chunks of vegetables, etc. so that you may have to use your teeth to eat it. In any event, it is rather thick and nourishing. This is why young children are soup fed.
"Un potage" has kept its somewhat posh connotation but it still refers to clear soup, that is so liquid you can drink it, with all ingredients processed with an electric mixer/blender. You should see your spoon through it.
To make "une soupe" become "un potage", you only have to mix the soup longer and add water or milk.
Now I'm curious... is there any dish that is "soup-like" but contains meat in French cuisine? In English, the generic term is "soup" but under that umbrella we have our stews, chowders, gumbos, broths, cream soups, purees, bisques, (oh yes we borrow shamelessly from French), etc.
In this sentence "on" is indefinite and strictly means "one". But because "one does not eat soup" is not the most natural way to make a statement about what people usually do, you can use other pronouns. If you are not English, you will probably say "they do not eat soup"; if you are English, you will say "we do not eat soup". So the pronoun "on" is very versatile and has several possible translations depending on context.