External hard drive dilemma - any help please?

Hello Mac World. I am looking for your help and a solution. I am relatively stupid in terms with most things technical. Basically I am looking to network 2 computers via ethernet for a graphic design enterprise and both of those computers need to be able to open and read and write the same files on an external hard drive. I need to do this cheaply so cannot afford a designated server costing $$$$'s. I am wondering if my only solution is to buy an external 1TB hard drive and switch(?) and connect that hard drive/switch(?) to both my computers via ethernet? Is this sensible or is there a better faster way to do this?

Thanks - please accept my apologies for what may seem an obvious question

You could also just connect the ext. to one computer and share the files on it using an app like Sharepoints.

Just my 0.02;D