Information Technology and Its Application in Business is designed to serve as a textbook for the second year B Com (Hons and Gen.) students of the University of Calcutta (CU). It covers those aspects of computer science and information technology (IT) which apply to the study of commerce subjects. Starting with an overview of IT and its relevance to business, the book delves into number systems and representation of data in a computing system, fundamentals of computers, data organization and database management system, data communication and computer networks, Internet, and Internet security. It also provides an exhaustive practical section covering several important topics. Written in a lucid style, the book provides numerous examples, self-explanatory figures and diagrams, and chapter-end exercises.