Portfolio vs. Gallery Advice?

Hello all,

I am a Neanderthal undergoing the WordPress learning process to create a website for my boss, who is an architect, and I am trying to build her a terrific portfolio for her site. This question is really a double-header: the first question is, what is the difference between a portfolio plug-in and a gallery plug-in?

My second question is, does anyone have a plug-in they would recommend which looks interesting, is not just a square grid (my boss has a thing against square grid portfolios), and has the capability to connect to other galleries, e.g. you can click on an image in the ‘residential’ gallery and it will take you to a gallery of images from that specific project?

Sorry, this is probably pretty simple, but I cannot find the answers easily on Google ??