Are the words in bold interchangeable in this context?
A network is a set of computers that are connected to each other so that information can be shared or sent to one computer to another. It is a global system of interconnected computer networks that/which links device worldwide.
I do not know whether to use which or that, or are they interchangeable?
Thanks!
In your example, the correct choice is "that". The extract begins talking about "a network", which could be a connection between as few as two computers. The purpose of that sentence is to define the word "network". The next sentence builds on that definition to introduce the idea of a much wider system of networks, one which connects computers worldwide. Consider the sentence
It is a global system of interconnected computer networks that links devices worldwide.
The meaning of the sentence is
That which connects computers worldwide is a global system of networks.
The referent of the word "it" is not the "network" defined in the previous sentence, but a network "which connects computers worldwide."
If the word "which" is used instead, the word "it" might be taken as referring to the simple "network" previously defined.
