According to the National Coffee Association, 54 percent of Americans over the age of 18 drink coffee every day (check out other cool coffee statistics here).

You may buy coffee or you may make it at home, but most of you probably know that there are several options for in either case. Do you want dark roast or light roast? Heck, do you want instant coffee or coffee grounds? Do you want coffee that tastes "earthy" or "fruity"? What does all of that even mean?

Here are some coffee basics that I think we all should know, and I mean coffee basics that would help you buy the coffee you want from the store.

There is a difference between different types of coffee "powder."

I know this sounds silly, but I know at least three people (myself included), that bought coffee grinds and thought it was instant coffee. When we got home and mixed our powder with hot water, we didn't exactly get the coffee that we wanted.

Instant coffee dissolves in water. It's basically brewed coffee (i.e. the liquid that you drink) that has been dried out, so when you add water you have

Coffee grinds are roasted coffee beans that have been ground into power. To brew coffee from these you usually need a coffee filter or a press (kind of the equivalent of a tea bag for tea leaves).

Lighter roast (generally) means more caffeine.

I was initially under the impression that darker roasts, which have a stronger flavour, also have more caffeine. Turns out, darker roasts are actually roasted longer so caffeine burns off. Some experiments say that there is a negligible difference, so dark vs. light roasts are more about your preference in taste.

Coffee can be acidic, but this is not necessarily a bad thing.

Acidity, with regard to coffee, can mean different things, including a "bright and sparkling sensation" in good coffee, pH level (black coffee is marked on the scale as below 5, which is lower than orange juice), or something that makes your stomach hurt after drinking coffee.

The last one is the most important to avoid, perhaps due to a doctor's recommendation or personal preference. In this case, darker roasts tend to have less acidity and some companies even specialise in low-acid coffee.

But as you can see, acidity isn't always bad. It contributes to a variety of fruity flavour notes in different types of coffee, which is something you may want.

Flavour notes really do vary; they probably won't overpower your drink, but they're important to think about.

Some packets of coffee at a store may say what type of "flavour notes" they contain, but this doesn't mean that the producer actually curated those flavours. For example, if coffee has a "peach" flavour the company didn't put peach extract into the grounds.

"Flavor notes are usually very subtle hints of identifiable tastes " in that particular coffee. Although they are subtle, it may be worth noting whether you like fruity or nutty or chocolatey flavours.

Buying any kind of coffee at a store is a huge commitment. You probably won't change it up after one cup, so make sure you get the right type for you!