What are reducing sugars ?

Sucrose is a non-reducing sugar. maltose and lactose are reducing sugars. why?

Both glucose and fructose are reducing sugars.

Which is a reducing sugar?

Which is not a reducing sugar?

In disaccharides, if the reducing groups of monosaccharides i.e. aldehydic or ketonic groups are bonded, these are non- reducing sugars. Which of the following disaccharide is a non-reducing sugar?

Distinguish between Reducing sugars and non-reducing sugars.