While the Microsoft Project 2013 Professional and Project Pro for Office 365 client is exclusively
used by people involved in detailed project planning and management processes, all other
participants and decision-makers only work with the browser-based Project Web App. The
advantage of solely using the Web App is that license costs are significantly lower. Project
participants can use Project Web App to access an overview of all the projects they have been
assigned to, view their work packages, and fill in their timesheets.