Object-Oriented Software Engineering (OOSE) is a software development approach that revolves around the concept of objects and classes. Ivar Jacobson, a renowned Swedish computer scientist, is one of the pioneers of OOSE. His book, "Object-Oriented Software Engineering: A Use Case Driven Approach," is a seminal work in the field. In this report, we will explore the key concepts of OOSE, discuss Ivar Jacobson's contributions, and provide information on the PDF and GitHub resources.