On a machine containing stuff you want others to use, you announce to the network what "resource" you will share with others. You give that resource a name by which it will be known to the network. That resource could be a printer or a disk folder (directory).
For example, if you want others to be able to view your "C:\\BadFarmGirlsAndGoats" folder, you right-click the "BadFarmGirlsAndGoats" folder name, pick the "Properties" option, then select the "Sharing" tab. This allows you to assign a network name (i.e., "DailyPrayers") to this folder and set a couple of other options.
Thereafter, other users on the network have the capability of adding access to this shared resource to their own machines. On these other machines, you'll use the "Map Network Drive" function.