Joining the Dots.
PCs, Printers, Scanners, Cameras and Storage Devices are now designed to connect together and interact with one and other but getting them to work together in harmony is not always easy. Computers can also be connected to home entertainment systems to broadcast streaming video and sound. They are also used as multimedia communication devices. A mobile phone can be connected to the Skype network and people are using webcams to communicate with each other.
The chances are, however, that many people have equipment that can communicate with other equipment but doesn't because configuring it all to function together can be complex and the task somehow doesn't ever get done.

When machines don't "talk" to each other.
Many people I've visited have had equipment which should work with other equipment but doesn't. The most common problem is getting a printer to print from all the PCs in the house. Another is getting PCs to share resources. I've known people who have fallen into the habit of copying documents onto floppy disks in order to print them from another PC. They know that it should be possible to use the printer from their laptop but have never quite worked out how to do it and so are forced to resort to inefficient methods. Most peripherals can be shared by all the PCs on the Local Area Network as long as they and the devices that they want to use are all configured to be members of that network.

Windows - When Simple File Sharing may be too simple.
Another problem is that having everything connected together is not always a good thing. You might have one hard drive which you want to keep private. How do you configure the network so that you can access it when you need to be able to do so yet keep its contents from prying eyes? Microsoft's "Simple File Sharing" is often too simple and two choices (i.e. on or off) are not always enough. Permissions can be complicated and Group Policy is sometimes hard to configure.