In another topic the OP asked for suggestions of "sweeter" red wines ("that aren't so tart and dry"). For some time I've been 'struggling' with a way to better understand what people most likely mean when they use the term "sweet" when describing wines that have no residual sugar (or not enough to really be 'sweet' - at least in the way that I perceive sweetness). This is usually more relevant to reds, but I frequently hear a dry reisling described as 'sweet', so it's something I need to understand better.
I THINK what people often refer to as sweetness is more what I would call 'fruitiness' (more intense fruit flavor, where the fruit is dominant), fruit-forward or highy extracted.
I try not to get too technical in discussing these kinds of things with people, but much of what I do is to help them select a wine they'll enjoy, so it really is rather important to know what they really mean. Of course, I also try to find out which specific varieties people prefer as a cross-reference tool.
Understanding that the vast majority of wine consumers (as with almost everything) use their most readily available references to describe things, I've generally equated sweet to fruit, or the absence of harsh or drying elements. Is that an over-simplification, or will it work in most situations? [Especially interested in Jason's take on this.]