[users] Sharing the /home Directories to all Users: This share exposes the whole of the directories under /home on the server to users on the LAN who can supply any valid Linux username + Samba Password pair.
Users can see other users’ directories and have read/write access to their own directories. This is a lower security share that the [homes] share.
Users on both Windows and Linux clients must authenticate (supply a correct username/Samba password). You can address these shares by drilling down in your network browser or by using the network addresses like smb://dell103/users or smb://dell103/users/a_username and also smb://192.168.1.2/…etc… Of course, Windows has a slightly different version of this addressing too (e.g. \dell103\users\john etc etc).
[groups] A Share for all Users: This share is accessible to all users. You must create the directory, groups, specified by the path parameter. Create it as root under the directory /home.
It will be a read-only share, great for sharing media or other archival files. If you want it to be a writable share you need to change the permissions on /home/groups from drwxr-xr-x to drwxrwxrwx. You can do that with the shell command sudo chmod 777 /home/groups.