See "carbohydrates", "complex carbohydrates", "integral grain" and so on.
Quite frankly, plain sugar from fruit is less dangerous than the complex carbs from grains. But fructose is still dangerous, just less so.
Cane sugar, a disaccharide, is split by digestion into its constituent glucose and fructose molecules, and the latter must be further processed by the liver. It is 50% fructose.
High fructose corn syrup is 55% fructose.
A variety of other sugars, such as maltose and lactose occur naturally in a variety of foods. However, they are in low enough concentrations to not be a health problem.
HFCS is from 42% - 55% fructose (the glucose obviously filling the remainder). Many uses are on the lower end.
A lot of people think the "high fructose" part of the name is relative to sucrose's 50:50. In reality it's relative to corn syrup which is almost entirely glucose, but some of the glucose can be processed to fructose to more closely match the sucrose that people are accustomed to. They go a little higher on the fructose because it is perceived as sweeter, so with a 55% ratio they can use less for the same sweetness.