It is a pay-as-you-go compute with zero long term commitment. Maximum flexibility, baseline cost structure.

It is a commitment-based billing model providing steep discounts (up to 70%) in exchange for a 1 or 3-year term.

It is a pure infrastructure reservation securing physical hardware slots in a specific Availability Zone(AZ). No built in billing discount.

Purchasing an unused AWS servers at massive discounts (up to 90% off). AWS can reclaim the servers with a 2 minute notice whenever they need the capacity back. Pay the current market price per second. If AWS interrupts you, you aren't billed for that partial hour.

It is nothing but multiple AWS accounts instance runs in a single hardware. It has secure software boundaries which isolates your data completely from others. Billing is standard flat rate per second/hour based on the instance size you choose, no extra fees.

Servers running on hardware dedicated entirely to your AWS account. It ensures you never share a physical machine with external companies, though different accounts of your own can share it. Pay the standard instance rate + a fixed regional fee (app 2$/hour) to keep the hardware isolated.

It is a physical server completely assigned to you, giving you full view of its hardware cores and sockets. You book the entire hardware machine and can manually control exactly which virtual server land on which CPU core. You pay for the entire physical server regardless of how many virtual instances you choose to run on it.