Amazon Prime Now has a narrower selection of groceries than Amazon Fresh does but doesn't require a subscription fee to use the Amazon prime now.
But that's the thing you'll get a less selection of groceries when shopping through prime now than with Amazon Fresh.
Amazon Fresh requires a subscription fee to use but they offer a wider variety of groceries that you can order through Amazon Fresh which is worth the subscription fee.
You can use Amazon Prime to buy some groceries and have them delivered even to a hotel or motel or your house but you can't choose from a lot of groceries like Amazon Fresh allows you too.
I would recommend signing up for the Amazon Fresh and pay the subscription fee if you want to as I find it's well worth the cost.