What is the difference between coffee grinds/beans labeled as "espresso coffee" and ordinary coffee? I was reminded of this curiosity just moments ago when I got a craving for coffee and couldn't find any normal coffee beans/grounds (owing to the fact that I don't normally drink coffee at home anymore).

I unwittingly purchased this so-called espresso coffee at a supermarket in the heart of the Italian district here, and most of the writing on it is Italian; I didn't even realize my mistake until after I had used it three or four times to brew normal coffee and saw, in very tiny letters, the words "espresso coffee" written on one of the sides.

So I shelved that coffee until today; even though it seemed fine, I figured I might have been using it inappropriately.  After my act of desperation today I decided to look this up.  According to Wikipedia:


  Espresso is not a specific bean or roast level; it is a coffee brewing method. Any bean or roasting level can be used to produce authentic espresso and different beans have unique flavor profiles lending themselves to different roasting levels and styles.


This is what I had always believed.  The answer to What factors lead to rich crema on espresso? does hint at a possible difference, though: It says that darker roasts are better for producing crema.  However, the coffee I have does not seem to be particularly dark a roast; it's dark, but I've had "normal" coffee that was darker.

Needless to say, I'm a little confused, and the internet is helping me a whole lot.  Maybe it's because the caffeine hasn't kicked in yet.

Is there an appreciable difference between coffee beans or coffee grounds labeled as "espresso coffee" and plain, ordinary coffee?  If so, what is it?

Perhaps more importantly, is espresso coffee suitable for use in a normal coffee maker or press?
It IS the roast that is the difference.  The only real difference in the beans is that some beans taste better at a higher roast than others, so they are more appropriate for espresso.  Your Italian grocery coffee company may be using the espresso label for marketing purposes, but in general, espresso coffee beans can be the same beans that are used for "regular" coffee, but roasted to a French or Italian roast level, which is darker than City or Full City.

Since the advent of Starbucks, many roasts are much darker than they used to be.  Dunkin' Donuts coffee, which is a Full City roast, used to be the norm, but now a French seems to be what you can buy.  

I roast my own coffee and take it to just into the second crack which is, generally, a Full City roast...a point where the character of the coffee predominates rather than the flavor of the roast.  There is more information about roasts at Sweet Marias where I buy my green beans, and reading through the site will give you way more of a coffee education than you probably ever wanted. 

So, yes, you can use the coffee you have to make brewed coffee.  It will probably be roastier than you would normally have, unless it is just a marketing ploy, in which case it will taste normal.  Consider how long you have had this coffee; if it has been shelved for a while "normal" probably won't be all that great, since freshly roasted coffee is, generally, way better than old coffee.  But as long as the oils aren't rancid, it is more likely just going to be bland.