Explanation
Oracle CloudInfrastructure 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
A fault domain is a grouping of hardware and infrastructure within an availability domain. Each availabilitydomain contains three fault domains. Fault domains provide anti-affinity: they let you distribute your instances so that the instances are not on the same physical hardware within a single availability domain.
A hardware failure or Compute hardware maintenance event that affects one fault domain does not affect instances in other fault domains. In addition, the physical hardware in a fault domain has independent and redundant power supplies, which prevents a failure in the power supply hardware within one fault domain from affecting other fault domains.
To control the placement of your compute instances, bare metal DB system instances, or virtual machine DB system instances, you can optionally specify the fault domain for a new instance or instance pool at launch time. If you don't specify the fault domain, the system selects one for you. Oracle Cloud Infrastructure makes a best-effort anti-affinity placement across different fault domains, while optimizing for available capacity in the availability domain. To change the fault domain for an instance, terminate it and launch a new instance in the preferred fault domain.
Use fault domains to do the following things:
Protect against unexpected hardware failures or power supply failures.
Protect against plannedoutages because of Compute hardware maintenance.
We can use fault domains to do the following things:
1) Protect against unexpected hardware failures or power supply failures.
2) Protect against planned outages because of Compute hardware maintenance

Explanation
A budget can be used to set soft limits on your Oracle Cloud Infrastructure spending. Youcan set alerts on your budget to let you know when you might exceed your budget, and you can view all of your budgets and spending from one single place in the Oracle Cloud Infrastructure console.
How Budgets Work:
Budgets are set on cost-tracking tags or on compartments (including the root compartment) to track all spending in that cost-tracking tag or for that compartment and its children.
All budgets alerts are evaluated every 15 minutes. To see the last time a budget was evaluated, open the details for a budget. You will see fields that show the current spend, the forecast and the "Spent in period" field which shows you the time period over which the budget was evaluated. When a budget alert fires, the email recipients configured in the budget alert receive an email.

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 abilityto 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.