"Other computers in your network" means all computers connected to the same wifi or router as your computer is connected.
If you want to share a file or folder with another computer on the same network, you can do this in two ways:
Option 1: With the option password enabled.
-In this case, you will need to create a user and password and configure the permissions for this new user in the computer that is sharing the file/folder, then to be able to access this file/folder the other computer will need to use the user and password created. This option is useful if you have several computers in the network, and each one can only access a specific file/folder.
Option 2:With the option password e disabled.
In this case, the "HomeUsers" group will manage the other computers access permission in the file/folder. This option is useful if you don't need to give different permission in the file/folder.