Virology provides information on viruses, which are associated with several emerging infectious diseases in both animals and plants. Most of the viral diseases are not curable and developing treatment strategy for these diseases is the real tough challenge for the researchers. It is possible only when all the information on its structure, replication, mode of transmission and especially methods of cultivating viruses are easily available. This will pay the way for understanding pathogenicity and targets for drug development. Prevention is better than cure suits better with the viral infections. Hence this course is developed to provide knowledge on nature, host and replication of different group of viruses, spread and management of viral diseases. The course also provides information on beneficial aspects of virus, especially its use in medicine and agriculture. The syllabus is designed keeping in mind the recent developments in virology and will be useful to all those who want to learn and update their knowledge on viruses.