Gig? A Lot? What's Enough?

Recently, we switched to fios for our internet. The fios rep sold my wife 1 gig. I don't know anything about this gig stuff, but I'm willing to bet 1 is more than we need. It's just me and my wife, we have 2 phones, 2 chromebooks, and an I-Pad. As soon as the rep heard that, she said we need a gig. But we can only use 2 at a time. Maybe I'll be watching a video, and she'll be playing a game. Other than that, we're on the net or texting.

I can't find a useful explanation of this gig stuff anywhere, and of course, on the fios site, I can't even find an offer of any gigs, let alone less gigs. (Or whatever you call it.)

Anyone know if we need a gig, and is it a lot?

We had crumcast, I mean comcast. We cut the cable tv a while ago, and now we got rid of crumcast entirely!! YEA! I can't stand crumcast!!!!! Where we live, there are few options. The fios just came through here, and not the tv aspect.

Side note: I intentionally did not capitalize comcast, crumcast or fios. It all sucks!