Infrastructure as Code (IaC) has become an important approach for automating the provisioning, configuration, validation, and management of cloud and software infrastructure. This review covers five aspects of IaC: DevOps integration, security, automation, compliance, validation, and risk management. By version controlling, testing, validating, and automating the deployment of infrastructure configurations, IaC makes infrastructure changes and deployments more efficient and automated, which enables continuous integration and continuous deployment. Security considerations include misconfigurations, hardcoded secrets, inadequate access controls, vulnerable third-party modules, supply-chain attacks, and configuration drift. Infrastructure governance is reinforced by automation and compliance mechanisms that validate the infrastructure in the interest of a policy, check the compliance at runtime, and enforce the policy automatically. Automated validation embeds shift-left principles, static analysis, unit testing and policy-as-code to catch errors and violations before they reach the end-users. The other elements of risk management are identification of risk, configuration drift, vulnerability management, risk assessment, threat detection and continuous risk monitoring. In conclusion, the review underscores the importance of implementing secure, scalable, and reliable IaC practices that incorporates automation, compliance, validation, and risk management in the infrastructure lifecycle. These practices help reduce human error, ensure deployment uniformity, adhere to regulatory requirements, and enhance organizational resilience through sustainable infrastructure security, auditability, flexibility and suitability for changing operational needs.