Work Breakdown Structures (WBS) refers to project key deliverables to organize teamwork into various manageable sections. According to Project Management Body of Knowledge (PMBOK), it is hierarchical work decomposition, deliverable oriented for execution by project team. It visually defines scope in manageable chunks to facilitate the understanding of the project team. Every associated level of WBS provides in-depth detail and definition. So one may consider it as the map or outline related to specific projects. It begins with the top deliverable or the project itself and then gives way to various sub deliverables.
What is WBS Diagram?
It is a graphical representation of project scope. It generally starts with box or graphic objects at top representing your entire project after this, sub components remain below the box. The box represents project deliverables and below each deliverable sub elements remains listed. These represent activities you need to perform for achieving the desired deliverables. While most times, drawing of the diagrams is based upon deliverables and sometimes it is possible to base them on project phases too. IT projects perfectly fit this model and most of these make use of WBS. It works as an input related to Gantt charts as well and does relate to project management.