Both Side Gigs and Side Hustles count as streams of income, but there is a difference between the two in the Two Chicks World.
The Side Gig is more like a permanent gig where there are no minimum hour or day requirements placed upon you by the company. You can basically pick the job when you want and put it down when you want. You can work at your leisure or not work at all. With a Side Gig you determine how you much you want to make. For instance if a side gig pays .10 cents per message and I need to earn a 10.00 a day. Then I know I need to type 100 messages to earn 10.00 dollars a day.
Side Hustles on the other hand are not permanent they come and they go. These positions you cannot determine how much you make, because it usually involves sharing a link or waiting on some one to sign up for a type of subscription sign up. This can even involve selling things. When you are selling you cannot determine how much money you will make. There is no way to determine how many people will buy your product. So the side hustle also allows for flexibility, but there is always the uncertainty of earning consistent income.