Amazon provide the popular Amazon cards and are available as email gift cards or physical cards, the cards can be found online and offline at stores like CVS Pharmacies and other amazon partners. These cards can only be redeemed at Amazon.com or endless.com (Amazon partner that sells shoes).
You can put from $5 to $5000 in amazon card and get it mailed to you or any recipient if you are buying it online. For offline you simply give the cash to the cashier and they will activate the card for you.