As computers dropped in price, joining them together became very popular – i.e. they were ‘Networked’ to share information.

But how are they to talk to each other? If company A sold a computer that cannot talk to company B’s computer, then life becomes very difficult. 

What is needed is a standard – a set of rules that every company will obey, so that their machines will know how to communicate. 

One such standard is called the ‘OSI Model’ (if you really want to know OSI stands for Open Systems Interconnect).