The build context is the set of files available to Dockerfile instructions. A .dockerignore file removes matching inputs before COPY uses them. This helps keep temporary logs, dependency directories and fictional private configuration out of an image built with a broad COPY. Check patterns against both excluded and retained files. A pattern that removes the application instead of the unwanted input can still produce a successful build with the wrong contents. These tasks use different exclusion shapes and inspect the resulting release filesystem. Image size in this workspace is a local model output, so compare included content rather than treating it as a vendor download measurement.