Explanation
https://www.oracle.com/assets/paas-iaas-pub-cld-srvs-pillar-4021422.pdf Enterprises demand more than just availability from their cloud infrastructure. Mission-critical workloads also require consistent performance, and the ability to manage, monitor, and modify resources running in the cloud at any time. Only Oracle offers end-to-end SLAs covering performance, availability, manageability of services.

Explanation
Changing the Shape of an Instance (Horizontal Scaling)
You can change the shape of a virtual machine (VM) instance without having to rebuild your instances or redeploy your applications. This lets you scale up your Compute resources for increased performance, or scale down to reduce cost.
Autoscaling (vertical scaling)
Autoscaling lets you automatically adjust the number of Compute instances in an instance pool based on performance metrics such as CPU utilization. This helps you provide consistent performance for your end users during periods of high demand, and helps you reduce your costs during periods of low demand.
As load increases, instances are automatically provisioned: the instance pool scales out. As load decreases, instances are automatically removed: the instance pool

https://docs.cloud.oracle.com/en-us/iaas/Content/Compute/Tasks/resizinginstances.htm

Explanation
Oracle Functions is a fully managed, multi-tenant, highly scalable, on-demand, Functions-as-a-Service platform. It is built on enterprise-grade Oracle Cloud Infrastructure and powered by the Fn Project open source engine. Use Oracle Functions (sometimes abbreviated to just Functions) when you want to focus on writing code to meet business needs.
The serverless and elastic architecture of Oracle Functions means there's no infrastructure administration or software administration for you to perform. You don't provision or maintain compute instances, and operating system software patches and upgrades are applied automatically. Oracle Functions simply ensures your app is highly-available, scalable, secure, and monitored. With Oracle Functions, you can write code in Java, Python, Node, Go, and Ruby (and for advanced use cases, bring your own Dockerfile, and Graal VM). You can then deploy your code, call it directly or trigger it in response to events, and get billed only for the resources consumed during the execution.

Explanation
You must create a dedicated virtual machine host before you can place any instances on it. When creating the dedicated virtual machine host, you select an availability domain and fault domain to launch it in. All the VM instances that you place on the host will subsequently be created in this availability domain and fault domain.
You also select a compartment when you create the dedicated virtual machine host, but you can move the host to a new compartment later without impacting any of the instances placed on it. You can also create the instances in a different compartment than the dedicated virtual machine host, or move them to difference compartments after they have been launched.
You are billed for the dedicated virtual machine host as soon as you create it, but you are not billed for any of the individual VM instances you place on it. You will still be billed for image licensing costs if they apply to the image you are using for the VM instances.
Read more: https://docs.cloud.oracle.com/en-us/iaas/Content/Compute/Concepts/dedicatedvmhosts.htm