Structural diversity of carbohydrates plays a crucial role in their large variety of roles in biological systems. This paper focuses on aspects of structure and biological functions of three classes of carbohydrates, N-linked oligosaccharides, blood group oligosaccharides, and glycosaminoglycans. Conformations and dynamics in solution, as well as the structure of protein-carbohydrate complexes are discussed. A short overview also describes theoretical and experimental methodologies that are used in current glycobiological research, particularly high-resolution NMR spectroscopy