A1 plotter/printers internal memory - what does it do?

[kippax]

Been lokking at a decent machine for the office. Found a couple of HP's that seem fine (can't post the model numbers as the info is at home).

 

However, what is the importance of internal memory and network cards on these machines ? They seem to add an awful lot to the price and I'm unsure whether we would make the most these features.