A progress report is a executive summary of the progress an individual (and his team) has made on a certain project over a certain time frame. An individual may report and explain the work that has been covered, resources spent, unexpected problems or instances that the project has undergone (if any), estimated time of completion, and other details concerning the project at hand.
A progress report is created to give the recipient (e.g. supervisors, managers, or office heads) an overview of the overall status report of a specific project. This gives them a chance to evaluate your performance, and request a few changes if necessary. They can also be informed of the problems which have affected and might affect the project.
Writing a progress report might not come easy to most people, especially for beginners. Still, a progress report is an important document which gives the writer a chance to communicate with the recipients.