The term 'infrastructure as code' in DevOps refers to the practice of managing and provisioning computing infrastructure through machine-readable definition files, rather than manual hardware configuration. This approach automates infrastructure setup, enabling faster deployments and consistent environments. It allows teams to version control their infrastructure, facilitating collaboration and reducing the risk of human error. As a key principle of DevOps, infrastructure as code supports agile methodologies and enhances overall operational efficiency by streamlining provisioning processes.