What this path is
Fulfilled by Amazon means you sell products on Amazon and Amazon handles storage, packing, and shipping. You still choose the product, pay for inventory, and own the customer problem when something goes wrong. The fee Amazon charges comes out of each sale, so the price has to cover the product, freight, Amazon fees, and the returns you will get.
Who it suits
This path suits someone who can research a product, place a manufacturing or wholesale order, and wait through shipping before any sale arrives. It is a poor fit if you need income this month, because inventory has to be paid for before it sells.
What it takes to start
You need an Amazon seller account, a product you can reorder, a way to inspect that product, and enough cash to buy the first batch plus freight into an Amazon warehouse. Many people start with a small test order rather than a container. You also need a plan for unsold units, because Amazon charges storage the longer a product sits.
Risks
A product can be copied, a listing can be suspended, freight can be delayed, and a batch can arrive damaged. Money tied up in unsold inventory is the risk that ends most first attempts. Treat the first order as a test you can afford to lose.
Go deeper
The starter guide for this channel is What it costs to start Amazon FBA. If you want to sell under your own brand, read How to get started with private label.
Questions
Does Amazon find the customers?
Amazon brings shoppers to the marketplace. You still have to earn the sale with the listing, the price, the reviews you earn over time, and sometimes ads.
Do you need a warehouse?
Not for FBA. Amazon stores the goods. You still need a place to receive and check a sample before you send a batch in.
Is this the same as dropshipping?
No. In FBA you own the inventory. In dropshipping someone else holds the stock and ships it after the order.