What are the differences between Project Online and Project Server?

Project Online and Project Server are actually different names for the same product.

If you want to install the software on the servers in the enterprise and use the application by connecting to this server, you must obtain a Project Server license. Project Online, on the other hand, is the provision of the software as a cloud service by being hosted on Microsoft servers.

If you have restrictions on keeping your data in the cloud, it is recommended to license Project Server. Otherwise, you can opt for Project Online licensing. Project Online will be more economical as a total cost.