Explanation
You can create and manage resources in the following ways:
Oracle Cloud Infrastructure ConsoleThe Console is an intuitive, graphical interface that lets you create and manage your instances, cloud networks, and storage volumes, as well as your users and permissions.
See Using the Console.
Oracle Cloud Infrastructure APIsThe Oracle Cloud Infrastructure APIs are typical REST APIs that use HTTPS requests and responses. See API Requests.
SDKsSeveral Software Development Kits are available for easy integration with the Oracle Cloud Infrastructure APIs, including SDKs for Java, Ruby, and Python. For more information, see Developer Resources.
Command Line Interface (CLI)You can use a command line interface with some services. For more information, see Developer Resources.
TerraformOracle supports Terraform. Terraform is "infrastructure-as-code" software that allows you to define your infrastructure resources in files that you can persist, version, and share. For more information, see Getting Started with the Terraform Provider.
AnsibleOracle supports the use of Ansible for cloud infrastructure provisioning, orchestration, and configuration management. Ansible allows you to automate configuring and provisioning your cloud infrastructure, deploying and updating software assets, and orchestrating your complex operational processes.
For more information, see Getting Started with Ansible for Oracle Cloud Infrastructure.
Resource ManagerResource Manager is an Oracle Cloud Infrastructure service that allows you to automate the process of provisioning your Oracle Cloud Infrastructure resources. It helps you install, configure, and manage resources using the "infrastructure-as-code" model. For more information, see Overview of Resource Manager.

Explanation/Reference:
https://www.oracle.com/cloud/pricing.html
https://www.brightworkresearch.com/oracle/2019/02/21/does-oracles-bare-metal-outperform-awss-bare-metal/

Explanation
IAM Group is A collection of users who all need the same type of access to a particular set of resources or compartment.
IAM DYNAMIC GROUP is A special type of group that contains resources (such as compute instances) that match rules that you define (thus the membership can change dynamically as matching resources are created or deleted). These instances act as "principal" actors and can make API calls to services according to policies that you write for the dynamic group.