If you do projects that are similar in structure, then instead of building your project plan from scratch every time, you can create and save those projects as templates to get a new project up and running quickly.
Using project templates
To create a new project from a template, click on Top Menu ▸ ▸ Project ▸ Use a Template
Managing project templates
Only administrators can create and manage project templates.
A template can be created from any project. To create or manage project templates, navigate to Top Menu ▸ ▸ Admin ▸ Project Management ▸ Project Templates