Glucose and fructose both have the formula #C_6H_12O_6#, but the atoms in these two compounds are arranged differently. What are glucose and fructose known as?
I'm not quite sure what the question is, but they're both sugars.
Glucose's IUPAC name is 6-hydroxymethyloxane-2, 3, 4, 5-tetrol
Fructose's IUPAC name is more complicated: (2R, 3S, 4R, 5R)-2-(hydroxymethyl)oxane-2, 3, 4, 5-tetrol
Both structures are cyclic.
For a good diagram of their structures try https://www.wolframalpha.com/input/?i=fructose