A GMS project is saved using the Save command. The project file is a binary file that stores all of the geometry and non-model input data.
To export individual components of a project to a text file, simply right-click on the item in the Project Explorer and select the Export option. To import individual files exported in this fashion, use the Open command in the File menu. When a project file is opened using the Open command, all of the files in the project are automatically opened.