This is a very basic way to compare plans. If you are looking to compare more features check out some of our other guides that help you compare those features.
Hosting with a company means you buy a set among of space on their server. This is called, "Storage". You store your website files there to be access at any time. The amount of storage is measured in gigabytes (GB's). Most plans that we have listed above are unlimited, but some have limits. These are shared server plans.
Transfer is how much data passed through the wire from your hosting company to the visitors of your website. It's also measured it GB's (usually). Most of the companies about are set to unlimited
Learn more about web hosting terminology