The study of viruses is known as virology. It involves the study of their sub-microscopic, parasitic particles and virus-like agents. It also focuses on their structure, classification and evolution, the ways in which they infect host cells the diseases they cause, and the ways to cure them. The study of retroviruses is known as retrovirology. A retrovirus is a kind of RNA virus. It inserts a copy of its genome in the host cell's DNA that occupies it thus changing the genome of that cell. Retroviruses are valuable research tools in molecular biology. These viruses are either single-stranded RNA or double-stranded DNA viruses. The main virion components in retroviruses are envelope, RNA, protein, etc. Retroviruses cause tumor growth and certain cancers in animals and in human beings, it causes diseases like AIDS. This book aims to shed light on some of the unexplored aspects of retrovirology and recent researches in this field. The various advancements in retrovirology are glanced at and their applications, as well as ramifications are looked at in detail. This book is a vital tool for all researching and studying this field.