Companies often have sets of similar projects that they wish to add to all their clients, or similar phases they wish to add to a group of projects.
Project analysis groups and phases may be identical across a set of projects. You can use a project template to apply these to new projects without having to set up all the details separately on a project-by-project basis.
Similarly, client analysis groups and projects may be identical across a set of clients. You can use client templates to apply these to new client without having to set up all the details separately on a client-by-client basis. You can also use client templates to assign default projects.