Having two different computers running different distributed projects in the same network is fine.
The way a network communicates (in a basic form before anyone rants at me) is by sending "Packets" of information through the network, depending on what type of network you have (Star, Ring or Bus - the 3 most common).
Most likely you have a star or ring network(most likely a star), as this is the most commonly used network layout. Star, Ring, Bus or any other network topologies are merely names for one method of network communication and the design of the network (the layout)
Although all networks may look the same, layout wise, all networks use a specific method of moving / communicating data around the network, each different network topology was originally designed for different environments.
On a star network each computer can “receive” the data, however if it is not “addressed” to that computer it ignores it and does not “read” the data, but the data carries on until it finds its destination.
A computer will send a test “Packet” that basically is sent to all the computers, if the computer can receive it, the “Packet” is received, and the target computer sends information back to your computer saying “I’m here and can receive packets” (hehe)
Ie giving confirmation that you can start / send whatever you want to do which requires network communication.
*(Topologies being the name given to represent a specific theory and method of network layout and communication)
(obviously this is not 100% accurate factual wise, but it gives her a basic understanding of a network)
Have alook at this if you like:
http://www.theteacher99.btinternet.co.uk/theteacher/gcse/newgcse/module7/task2.htm