What are entities linked using relationships in a project?

When discussing entities linked using relationships in a project, activities are indeed the correct choice. In project management, activities represent the specific pieces of work required to achieve project objectives. These activities often have dependencies and relationships with one another, indicating the sequence in which they need to be performed.

For instance, in a project timeline, certain activities must be completed before others can commence, establishing a clear relationship among them. This is fundamental for effective project planning and scheduling, as it ensures that resources are allocated efficiently and deadlines are met.

While tasks, milestones, and resources are also important components of project management, they serve distinct purposes. Tasks may refer to individual actions within activities, milestones indicate significant points or goals within the project timeline, and resources encompass the people, equipment, and materials needed to carry out the activities. However, it is the activities that primarily define relationships and dependencies within the project framework.