For readers outside the U.S., American biscuits can be scone-like, depending on the recipe. Some are high rise and puffy/fluffy, others are less lofty and have a more dense, drier and crumblier texture, similar to a scone. Whatever the recipe, American biscuits are usually round and perhaps 2 inches in diameter, so they are smaller than the average scone. They can be eaten any time of day, but are most popular at breakfast, seved hot, split and filled with butter and/or jam. As others have mentioned, a split biscuit smothered with a rich creamy gravy flecked with bits of breakfast sausage is a very popular quick breakfast dish in the South and parts of the Midwest. (It's not considered to be a very high-class dish, however, so for some people it's a bit of a secret vice.) American biscuits are savory, not sweetened. Some popular fluffy versions are made with buttermilk. A famous, but extremely labor-intensive traditional variety is called beaten biscuits, because the dough is literally pounded with a hammer for at least half an hour to achieve the desired texture! Some very light and luxurious biscuits are called spoon biscuits or spoon bread. In another popular variation, cheddar cheese and perhaps some herbs are added to the dough. The ubiquitous American chain restaurant called Red Lobster is famous for theirs, and many people are addicted to them! That recipe can also be baked in a loaf pan as a quick bread and served sliced.
In addition to being eaten on their own or with sausage gravy, biscuits can serve as a nice alternative topping to casseroles like shepherd's or cottage pie, or to top a pot pie. The biscuits are just laid on top of the filling and baked until they are done and golden brown on top. You can be as creative as you wish with the dough! If you are curious by now, you can find endless recipes here on EYB in American cookbooks and also online at U.S. food sites. If you go online there will be lots of pictures of biscuits, so you know what they look like!
One famous variation, especially in the South, is to bake a single large round biscuit of the scone-like crumbly type in an 8 or 9-inch cake or pie dish. After it's cool, the biscuit is split horizontally in two, and filled with cut strawberries and whipped cream, which can also cover the top layer of the biscuit, as well. This is what Americans traditionally call Strawberry Shortcake. It is sometimes seen made with layers of sponge cake rather than biscuit, but purists know that it's totally inauthentic! The real thing is made with biscuit layers.
If it's available where you live, the American ready-made dry biscuit mix called Bisquick is a useful shortcut. Just follow the recipes on the box. My mother has used it forever, although she has switched loyalties to the store brand sold at Aldi's in the U.S., which she swears is even better than the original mix! Outside the U.S. you may be able to find it at shops that cater to homesick American expats, or you can order it on Amazon. You can also make your own -- just look for homemade biscuit mix recipes online. The mix is basically flour into which oil or shortening has been cut in, plus some leavening agent like baking powder or baking soda.