A workspace is a state in the backend of TYPO3 CMS. Basically there are two types of workspaces: LIVE workspace: this is exactly the state TYPO3 CMS has always been in. Any change you make will be instantly live. Nothing has changed, it just got a name. Access to the Live workspace must be explicitly granted to backend users and groups (in the "Mounts and Workspaces" tab)....
The first result when search for "workspaces" https://docs.typo3.org/search/search?scope=&q=workspaces is a broken link: