"In the U.S. the term sweet pepper covers a wide variety of mild peppers that, like the chile, belong to the capsicum family. The best known sweet peppers are bell peppers, named for their bell-like shape. They have a mild, sweet flavor and crisp juicy flesh. When young most bell peppers are a rich, bright green, but there are also yellow, orange, purple, red and brown bell peppers. Red bell peppers are green bell peppers that have ripened longer and are very sweet. The red heart-shaped pimiento is another popular sweet pepper. Pimientos are the familiar red stuffing found in green olives. Other sweet pepper varieties include cachucha, European sweet, bull horn (thin, curved and green); Cubanelle (long, tapered, yellow to red); and sweet banana pepper (long, yellow, banana-shaped)."
Pretty clear and concise. And why then do red peppers cost more than the green? Apparently, it is the fact that because they are completely ripe, spoilage rates are higher. But, why buy them when they are so easy to grow? In my research I found a really good site that goes into peppers in great depth. They particularly cover the nutritional value very well here. OK, now I can harvest my peppers and make some spaghetti sauce!