You can set permissions for items on macOS if you wish. Permission settings allow you to select who can view and modify files on your Mac. You change the permission settings at the bottom of the Info window for a file, folder or disk in the Finder.
(Finder is the home base for the Mac. You use it to organize and access almost everything on Mac, including documents, photos, movies and other files you have.)
OK, back to permissions. For example, you can change permission settings for a folder so that other users who sign in to your Mac or connect to it for file sharing can see, but not change files in a folder. To assign permissions to users and groups:
Select a disk, folder or file, and then choose File> Get Info.
If the information in Sharing and Permissions is not visible, click the triangle.
Click the lock icon to unlock it and enter an administrator name and password.
Click a user or group in the Name column, and then select a privilege setting from the pop-up menu. Read and write allows a user to open the item and change it. Read only lets a user open the item, but not change the content. Write only allows users to copy items to the drop box, but do not open it. Only the owner of the drop box can open it. No access blocks all access to the item.
You can also use permissions for all items in a folder or disk. To do so:
Select a folder or disk and then choose File> Get Info.
Click the lock icon to unlock it, and then enter an administrator name and password.
To change a product's owner:
Select the item, then choose File> Get Info.
Click the lock icon to unlock it, then enter an administrator name and password.
If the new owner's name is not listed in the Name column in the Sharing and Permissions section, click the Add button to add
Select the new owner in the Name column:
Select an item , then choose File> Get Info.
If you do not own the item, click the lock icon to unlock it and then do one of the following:
Add a user or group: Click the Add button below the list, select a user or group, and then click Select.
Remove a user or group: Select user or group, and then click Remove button below the list.
You can undo changes made in the sharing and permissions section of an information window since the opening, except using permissions for all items in a folder or disk. Here's how:
Make sure that the information window remains open when you have made the changes.
Click the Action pop-up menu, and then select "Restore Changes."
Batch changes to file permissions
You can even make batch changes to file permissions. This can be a great time saver because you do not need to select files to determine who can access or view them. You can change permissions for files in the same folder or for all files on any drive. Here's how:
Select disk or folder with the files, then click "Get Info." If the Sharing and Permissions option does not appear, click the triangle to make it visible.
] Click on the lock icon and enter your username and password. (You need a password to access your Mac, not?)
Click on the username or group name you want to give, edit or deny permissions.
Select the level of permissions you want the user or group to have in the pop-up window.
Click on the gear icon, and then click Apply to attached articles. Note that if you select "No access" at the permission level, that person or group will no longer be able to add to a folder or see any items in the folder.