Aquafaba explained

When we refer to aquafaba... we’re talking about the liquid in a can of chickpeas... The starchy liquid is a great binder directly from the can, but what really makes it magical is that it whips and creates a foam. Aquafaba is therefore able to trap air, giving items structure at the same time it delivers a fluffy crumb and lift...

We fold this foam into blueberry muffins to lighten them, and we whip aquafaba with sugar and vanilla to make egg-free meringues... 

As it does with egg whites, adding a stabilizing ingredient improved the structure of whipped aquafaba. In sweet recipes, we usually used sugar. But there’s another ingredient we often whip into egg whites to add stability: cream of tartar. But why?

Cream of tartar is acidic—when added to egg whites, it prevents the egg proteins from bonding too tightly to each other and denatures them so they can create a foam that traps air bubbles and water more quickly and holds them in place for less weeping...

For ease, we like to freeze aquafaba in 1-tablespoon portions in ice cube trays. Once the bean liquid cubes are frozen solid, they can be transferred to a freezer bag for future use. Frozen-then-thawed aquafaba whips just as well as fresh aquafaba.

More information at America's Test Kitchen.