Links to Relevant Wiki Articles(s):
Cloud variables allow for data from a project to be saved and shared with other people in the Scratch community. You can use cloud variables to make surveys and other projects where others in the community can access and modify the data over time.
When you interact with a project using cloud variables, the data associated with your interactions can be stored along with your username and can be viewed by others.
Only numbers can be stored in cloud variables.
If you see anything inappropriate in cloud variables, click the "Report" button (under on the project player on the project page). Make sure that you mention "cloud variables" when you type your reason in the report.