Locking helps users share reports with other users without allowing them to make any permanent edits. All changes made by users on a locked report revert back to the original state at the end of a session or a report refresh. Once a report is built, it's recommended to lock it since you would always want to do ad-hoc analysis and not change the report.
Once locked, a report can be unlocked again by any user with creator-level access to the report. We've also added the following states to help you recognize the status easily:
"Edits are being saved" - You are an editor or creator of the report, and the report is not locked.
"No edits are being saved" - You have explorer access to the report and/or the report is locked, so changes made by you are not being saved.
We recommend locking important reports that are accessed by multiple users in your team, to ensure that any ad-hoc changes made by creators/editors do not affect other users' views.