GitLab can be used to deploy applications to various AWS services through its integration with AWS and GitLab CI/CD pipelines. It allows deploying to Lambda, Fargate, EKS, ECS, and EC2. For each service, the document provides instructions on setting up the necessary IAM roles and configuring a GitLab CI pipeline to deploy code. This allows development teams to manage the entire software development lifecycle from a single interface without needing separate tools for each AWS service.