This chapter provides background information regarding glycome informatics, which will be required for understanding the methods introduced. It describes the nomenclature for representing glycans in computerized form. The chapter focuses on glycan-related interactions, including an introduction to lectins and their interactions, and carbohydrate-carbohydrate interactions. Due to the development of glycan databases at around the same time but independently of one another, several formats for representing glycan structures have been developed. The KEGG Chemical Function (KCF) format for representing glycan structures was originally used to represent chemical structures in KEGG. Linear Code® is a carbohydrate format defined by GlycoMinds, Ltd. GlycoCT was developed as a part of the EuroCarbDB project, and it is used as the main format in the GlycomeDB database. Several XML representations for characterizing glycan structures to ease data transfer and exchange have been developed. Linear Code® is a carbohydrate format defined by GlycoMinds, Ltd.