Copyright, Trademark, and Patent - an overview for Newbies.
Many of us know nothing of legal jargon except what we've heard on Law & Order or The X-Files (myself included). Because of this language barrier, it's difficult to know what kind of protection we would need if someone tries to take credit for something we created. For these people I have broken down the differences between a copyright, a trademark, and a patent. This way you know where to start when you look into protecting the rights of your original creations.
A copyright protects works of expression; this would be your novel, poem, artwork, music, film, etc. Copyrights prevent people from using your content without your permission, as long as it's registered in your name of course.
You write a poem and have it copyrighted, then someone writes a song but uses your poem as lyrics without your permission. This would be considered illegal and that person would be issued an order to no longer use your work, and you may be awarded monetary damages if they made money off of your work.
A trademark protects aspects of the work itself, such as logos, titles, symbols, slogans, catch phrases, distinctive words, product design or any other way a person or organization would identify themselves or their work.
Say you wrote a book called Star Wars but it's not about Luke Skywalker and company, it's about celebrity cat fights. That title is already trademarked, so you can’t use it regardless of what the book is about. So be prepared to change your title to Slut Wars, because George Lucas is the last person you'd want to cross on this issue. He's currently in litigation to get the US Government to rename it's Star Wars weaponry program.
A patent protects inventions, products, and original ideas from being used commercially without permission.
If you invent a cup that can't spill, a patent would not only prevent anyone else from using or selling your exact invention, but you also may be entitled to monopoly rights so that nobody can manufacture or sell any similar type of cup for 20 years from the date you filed.
The product design itself (i.e. the shape of the cup, the colors used, etc) could be trademarked and used as a way to identify your product.
I hope this little overview helped answer some of your questions. For further research on protecting your creative rights, there are numerous online resources. I highly recommend the NOLO law encyclopedia http://www.nolo.com.