CloudFormation is an AWS (Amazon Web Services) service that provides a common language for describing and provisioning all the infrastructure resources in a cloud environment. Using CloudFormation templates written in JSON or YAML, developers can define the desired state of their infrastructure and let CloudFormation handle the provisioning and configuration. This approach enables infrastructure as code (IaC), allowing for version control, reproducibility, and automated deployment of resources. CloudFormation simplifies the management of AWS resources, ensuring consistency and reducing the risk of manual configuration errors.