Biscuits (Cookies) are a kind of baked treat, a sort of a small bread with a firm browned crust and a soft interior. You can’t give an unequivocal description, because there are countless possible variants. To give an example, biscuits can theoretically be both sweet and savory.
The noun comes from Latin “panis biscotus”, meaning twice baked bread, as it was born as a storable version of bread: the ship’s biscuit, inexpensive and long-lasting, even in case of rough handling.
In the early 19th century, a pastry-maker decided to add butter and sugar to the usual dough. And that’s how the modern biscuit was born. Nowadays, the base ingredients are sugar, eggs, butter, flour and baking powder.
In cooking, we have plenty of recipes with biscuits or to make biscuits. Here in Italy, is is a staple food for breakfast, but we also eat it for an afternoon snack, for axample. Savory biscuits can be used as a base for some dishes. And as regards sweet biscuits… you can make them with jam, or chocolate, or candied fruit, or spices… You can use them to garnish ice creams or cakes. And as a base to make cheesecakes!
There is no way in which you can state biscuit nutritional fact, as there are too many variants in biscuit ingredients (and in biscuit dimensions, too). Anyway, it usually is rich in sugar and butter. So it isn’t a light food. But if you make biscuits at home, at least they won’t contain additives or artificial colouring.