Deployment is the process of getting code and configuration changes from your development environment to production. A typical Drupal deployment workflow involves pulling the latest code, running composer install, importing configuration with drush cim, running database updates with drush updb, and clearing caches with drush cr.
Most teams automate this sequence through a deployment script or CI pipeline, which eliminates human error and makes deployments repeatable.
Specialised hosts like Pantheon and Acquia provide deployment workflows out of the box, often with staging environments and one click promotion to production. For self managed setups, tools like Ansible, Deployer, and custom shell scripts handle the job well. Always test deployments on a staging environment that mirrors production before pushing changes live. This catches environment specific issues before they affect real users.