Project management plays a key role in leveraging project success in organizations. However, regardless of the quality of management, it is normal that changes occur during the development of information technology and information systems projects, which are almost inevitable. These changes may relate, for example, to the requirements, the cost of resources, the time available for carrying out the activities, the loss of human resources, among many others. Thus, it is essential to analyze the impact of these changes before they are accommodated in the project so that the success of the project is not affected. This article presents a review of key concepts on project changes, including the causes, types, and impacts of changes.