What's the difference, you ask? Actually, a friend of mine asked exactly that just a few days ago, and it occurred to me that not everyone may have the benefit of that knowledge. Of course, I address the subtle differences between the two populations in the book, but I'm happy to offer a high-level synopsis here for your consideration.
First, a redneck's habitat is the southern United States. Period. Some may have migrated to other regions, but they have likely done so out of necessity or under extreme duress. The term "redneck" is slang and refers to a member of the Southern white rural laboring class. A white laborer who works outdoors will probably have a red neck; turtleneck shirts are worn only during the winter, otherwise known as the last full week of February here in Georgia. Calling someone a redneck is not always intended as a slur and in fact may be received as a compliment - to a bona fide redneck, that is. While many redneck characteristics are considered unappealing to more refined folks, a redneck is not known for scamming, mooching or otherwise fleecing upstanding citizens. They're simply people who enjoy the, um, "southern country" side of life with a sometimes undignified flair. They are honest, hardworking folks.
The difference between rednecks and white trash, in a word, is "ignorance." White trash children are taught practically from birth to carry the torch – white trash parents USUALLY beget white trash offspring. Occasionally a kid will come along who's smart enough to look through the bars of his crib and say to himself, "No way. There has to be something better." But more often than not, that same little kid will be peeping through bars of one sort of another his entire life. A little white trash kid grows up seeing his parents cheat the system, scam relatives, steal from friends (or strangers; they're not picky), anything to keep from actually working. Working would only take time away from the true white trash passion of drama. They love drama, and it takes precious time and resources to create it and keep it going. Drugs, domestic violence, petty crime, repeated unplanned pregnancies and endless incarcerations have been voted the Top 5 Most Fun White Trash Activities in the United States. I read that in some consumer advice magazine recently.
Oh one more thing, white trash have been found in every inhabited region of the world, including Iceland and Antarctica. I believe in those inhospitable regions they are referred to simply as "cockroaches." Don't laugh; they have a knack for survival and will outlive both you and me.