When versioning is enabled for a project, the upload process includes a system check for files with the same name as existing files in the target folder. These files are identified as candidates for versioning and will show in blue lettering:
The application will do a checksum of the file for data changes. If changes in the file are identified, the file version will increment. In the image below, the original name of the file remains with a visual indication (V2) of the file's version.
If multiple versions exist for the file, the File History window will turn a yellow tint and will include additional features:
The Go to version dropdown allows you to select a version of the file (by default, the most recent version is selected). The tabbed areas will display only the information for the selected version.