Explanation
Oracle Cloud Infrastructure is a set of complementary cloud services that enable you to build and run a wide range of applications and services in a highly available hosted environment. Oracle Cloud Infrastructure offers high-performance compute capabilities (as physical hardware instances) and storage capacity in a flexible overlay virtual network that is securely accessible from your on-premises network.

Explanation
Horizontal scaling means that you scale by adding more machines into your pool of resources whereas Vertical scaling means that you scale by adding more power (CPU, RAM) to an existing machine.
An easy way to remember this is to think of a machine on a server rack, we add more machines across the horizontal direction and add more resources to a machine in the vertical direction.

With horizontal-scaling it is often easier to scale dynamically by adding more machines into the existing pool
- Vertical-scaling is often limited to the capacity of a single machine, scaling beyond that capacity often involves downtime and comes with an upper limit.

Explanation/Reference: https://blogs.oracle.com/cloud-infrastructure/oracle-functions-now-generally-available

Explanation
Oracle Cloud Infrastructure Archive Storage is the lowest pricing for storage (per GB)

Explanation
A NAT gateway gives cloud resources without public IP addresses access to the internet without exposing those resources to incoming internet connections.
NAT is a networking technique commonly used to give an entire private network access to the internet without assigning each host a public IPv4 address. The hosts can initiate connections to the internet and receive responses, but not receive inbound connections initiated from the internet.