Resource Manager is an Oracle Cloud Infrastructure service that allows you to automate the process of provisioning your Oracle Cloud Infrastructure resources. Using Terraform, Resource Manager helps you install, configure, and manage resources through the “infrastructure-as-code” model.
A Terraform configuration codifies your infrastructure in declarative configuration files. Resource Manager allows you to share and manage infrastructure configurations and state files across multiple teams and platforms. This infrastructure management can’t be done with local Terraform installations and Oracle Terraform modules alone. For more information about the Oracle Cloud Infrastructure Terraform provider, see Terraform Provider. For a general introduction to Terraform and the “infrastructure-as-code” model, see https://www.terraform.io.

You can set up a single IPSec VPN with a simple layout that you might use for a proof of concept (POC).
Referenz:
https://docs.cloud.oracle.com/en-us/iaas/Content/Network/Tasks/settingupIPsec.htm It is possible to set up a site-to-site Virtual Private Network (VPN) Connection between your on-premises network (a data center or corporate LAN) and your Oracle virtual cloud network (VCN) over a secure encrypted VPN. The VPN connection uses industry-standard IPSec protocols. The Oracle service that provides site-to-site connectivity is named VPN Connect (also referred to as an IPSec VPN).

Cloud Horizontal Scaling refers to provisioning additional servers to meet your needs, often splitting workloads between servers to limit the number of requests any individual server is getting. In a cloud-based environment, this would mean adding additional instances instead of moving to a larger instance size.
Cloud Vertical Scaling refers to adding more CPU or memory to an existing server, or replacing one server with a more powerful server.
Referenz:
https://cloudcheckr.com/cloud-cost-management/cloud-vs-data-center-what-is-scalability-in-cloud-computing/ 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.

A NAT gateway gives cloud resources without public IP addresses access to the internet without exposing those resources to incoming internet connections.

Oracle Cloud Infrastructure offers two distinct storage class tiers to address the need for both performant, frequently accessed “hot” storage, and less frequently accessed “cold” storage. Storage tiers help you maximize performance where appropriate and minimize costs where possible.
Use Object Storage for data to which you need fast, immediate, and frequent access. Data accessibility and performance justifies a higher price to store data in the Object Storage tier.
Use Archive Storage for data to which you seldom or rarely access, but that must be retained and preserved for long periods of time. The cost efficiency of the Archive Storage tier offsets the long lead time required to access the data.
Unlike Object Storage, Archive Storage data retrieval is not instantaneous.
Referenz:
https://oracledbwr.com/oracle-cloud-infrastructure-object-storage-service/

The Oracle Cloud Infrastructure Load Balancing service provides automated traffic distribution from one entry point to multiple servers reachable from your virtual cloud network (VCN). The service offers a load balancer with your choice of a public or private IP address, and provisioned bandwidth.
A load balancer improves resource utilization, facilitates scaling, and helps ensure high availability. You can configure multiple load balancing policies and application-specific health checks to ensure that the load balancer directs traffic only to healthy instances. The load balancer can reduce your maintenance window by draining traffic from an unhealthy application server before you remove it from service for maintenance.
HOW LOAD BALANCING WORKS:
The Load Balancing service enables you to create a public or private load balancer within your VCN. A public load balancer has a public IP address that is accessible from the internet. A private load balancer has an IP address from the hosting subnet, which is visible only within your VCN. You can configure multiple listeners for an IP address to load balance transport Layer 4 and Layer 7 (TCP and HTTP) traffic. Both public and private load balancers can route data traffic to any backend server that is reachable from the VCN.
1) Public Load Balancer
To accept traffic from the internet, you create a public load balancer. The service assigns it a public IP address that serves as the entry point for incoming traffic. You can associate the public IP address with a friendly DNS name through any DNS vendor.
A public load balancer is regional in scope. If your region includes multiple availability domains, a public load balancer requires either a regional subnet (recommended) or two availability domain-specific (AD-specific) subnets, each in a separate availability domain. With a regional subnet, the Load Balancing service creates a primary load balancer and a standby load balancer, each in a different availability domain, to ensure accessibility even during an availability domain outage. If you create a load balancer in two AD-specific subnets, one subnet hosts the primary load balancer and the other hosts a standby load balancer. If the primary load balancer fails, the public IP address switches to the secondary load balancer. The service treats the two load balancers as equivalent and you cannot specify which one is “primary”.
Whether you use regional or AD-specific subnets, each load balancer requires one private IP address from its host subnet. The Load Balancing service supplies a floating public IP address to the primary load balancer. The floating public IP address does not come from your backend subnets.
If your region includes only one availability domain, the service requires just one subnet, either regional or AD-specific, to host both the primary and standby load balancers. The primary and standby load balancers each require a private IP address from the host subnet, in addition to the assigned floating public IP address. If there is an availability domain outage, the load balancer has no failover.
2) Private Load Balancer
To isolate your load balancer from the internet and simplify your security posture, you can create a private load balancer. The Load Balancing service assigns it a private IP address that serves as the entry point for incoming traffic.
When you create a private load balancer, the service requires only one subnet to host both the primary and standby load balancers. The load balancer can be regional or AD-specific, depending on the scope of the host subnet. The load balancer is accessible only from within the VCN that contains the host subnet, or as further restricted by your security rules.
The assigned floating private IP address is local to the host subnet. The primary and standby load balancers each require an extra private IP address from the host subnet.
If there is an availability domain outage, a private load balancer created in a regional subnet within a multi-AD region provides failover capability. A private load balancer created in an AD-specific subnet, or in a regional subnet within a single availability domain region, has no failover capability in response to an availability domain outage.

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.

Oracle Cloud Infrastructure is hosted in regions and availability domains. A region is a localized geographic area, and an availability domain is one or more data centers located within a region. A region is composed of one or more availability domains. Most Oracle Cloud Infrastructure resources are either region-specific, such as a virtual cloud network, or availability domain-specific, such as a compute instance. Traffic between availability domains and between regions is encrypted.
Availability domains are isolated from each other, fault tolerant, and very unlikely to fail simultaneously. Because availability domains do not share infrastructure such as power or cooling, or the internal availability domain network, a failure at one availability domain within a region is unlikely to impact the availability of the others within the same region.
The availability domains within the same region are connected to each other by a low latency, high bandwidth network, which makes it possible for you to provide high-availability connectivity to the internet and on-premises, and to build replicated systems in multiple availability domains for both high-availability and disaster recovery.
A fault domain is a grouping of hardware and infrastructure within an availability domain. Each availability domain 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.

https://www.oracle.com/in/cloud/pricing.html
– OCI offers consistent performance with a predictable pricing model – is the best suited answer.
– Only bare metal workloads are supported in OCI – False, since you can work with VMs etc too
– With OCI, you can run cloud native workloads – False, since you can work with on-premise by connecting it to OCI too.
– With OCI, you can only run Java based workloads on bare metal – False since Java is not the only programming language supported by OCI.

Oracle Cloud Infrastructure Archive Storage is the lowest pricing for storage (per GB) Reference:
https://www.oracle.com/cloud/storage/pricing.html

Archive storage as seen above is the cheapest!

You can do Costs Analysis in OCI and you can group and filter the cost by Tags or compartments To filter costs by dates To filter costs by tags To filter costs by compartments To remove a compartment or tag filter