Modern Art or Contemporary Art - What's the difference?

The key point here is that there is, indeed, a difference between the two. Sure, this is counterintuitve to any other usage of "modern" and "contemporary", wherein the two words are largely interchangeable. You wouldn't want to mix up this little Art minefield in front of a snooty gallery salesperson, believe me.

Personal aside: I am keenly interested in exploring the Contemporary Art scene of the 1970's. (Frankly, I "came of age" in this decade and could use a good deal of memory-jogging. Times were different then, kids, and much of the 70's is a pleasantly out-of-focus video that seems to have been poorly edited for content. Hope some of my fellow Boomers are nodding and grinning, and it wasn't just me...) It's a blessing to be able to share while catching up!

Edit:

After four years of emails and comments (including the one I just deleted, in which some joker named me@mine.com basically called me a dumb@$$) it has become clear to me that some of you read too quickly. So I'm going to spell this out in little words:

• This is a blog post.
  
• It points to articles.
  
• The articles are hyperlinks in the title of this blog post.
  
• Hyperlinks are web devices that take you to anchor text or other pages.
  
• In this case, the "other pages" would be definitions of Modern and Contemporary Art, respectively.
• The definition pages will answer the question that this blog post will not.

If the above is not sufficiently clear for every literate human, here is the definition of Modern Art, and here is the definition of Contemporary Art. Hint to me@mine.com: try to click on the blue text, Dear, OK? Where it says "definition of Modern Art" and "definition of Contemporary Art," do you see them? No, please don't trouble yourself to scroll all the way up to the hyperlinks in the title. First sentence of this paragraph, all right? Nothing too strenuous for you, I hope. Can you click on those two blue dealies? Great! I knew you could. There, see? Two clicks and question answered! Hyperlinked definitions v. blog post! Yay, you!

/Edit

Today (July 10) in Art History:

• James Abbott McNeill Whistler (American painter and engraver), born in 1834


• Giorgio de Chirico (Italian painter), born in 1888