ExplanationA shape is a template that determines the number of CPUs, amount of memory, and other resources that are allocated to an instance.
Standard shapes don't incur costs in a STOPPED state.

Reference: https://docs.oracle.com/en-
us/iaas/Content/Balance/Concepts/balanceoverview.htm#ariaid-title1

Oracle Cloud Infrastructure Service Level Agreement (SLA): 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.
Oracle PaaS and IaaS Public Cloud Services - Pillar Document (PDF) > Availability: Rest assured that your cloud workloads are in continual operation with Oracle's commitments to uptime and connectivity. > Manageability: The elasticity and configurability of infrastructure is part of why people move applications to the cloud. Your services need to be manageable all the time to deliver this benefit.
Oracle provides manageability SLAs to ensure your ability to manage, monitor, and modify resources. > Performance: It's not enough for your IaaS resources to be merely accessible. They should consistently perform the way you expect them to. Oracle is the first cloud vendor to guarantee performance, so you can rely on your infrastructure for enterprise applications. Reference:
https://www.oracle.com/cloud/iaas/sla.html

Reference: https://docs.oracle.com/en-us/iaas/Content/Network/Tasks/servicegateway.htm#ariaid- title1

Explanation
When you work with Oracle Cloud Infrastructure, one of the first steps is to set up a virtual cloud network (VCN) for your cloud resources.
VIRTUAL CLOUD NETWORK (VCN) :
A virtual, private network that you set up in Oracle data centers. It closely resembles a traditional network, with firewall rules and specific types of communication gateways that you can choose to use. A VCN resides in a singleOracle Cloud Infrastructure region and covers a single, contiguous IPv4 CIDR block of your choice.
See Allowed VCN Size and Address Ranges. The terms virtual cloud network, VCN, and cloud network are used interchangeably in this documentation. For more information, see VCNs and Subnets.
SUBNETS :
Subdivisions you define in a VCN (for example, 10.0.0.0/24 and 10.0.1.0/24). Subnets contain virtual network interface cards (VNICs), which attach to instances. Each subnet consists of a contiguous range of IP addresses that do not overlap withother subnets in the VCN. You can designate a subnet to exist either in a single availability domainavailability domain or across an entire region (regional subnets are recommended). Subnets act as a unit of configuration within the VCN: All VNICs in a given subnet use the same route table, security lists, and DHCP options (see the definitions that follow). You can designate a subnet as either public or private when you create it. Private means VNICs in the subnet can't have public IP addresses. Public means VNICs in the subnet can have public IP addresses at your discretion. See Access to the Internet.