... is a concept of automatization of repeatable actions such as compiling, bundling, testing, delivering and deploying your software. You can get more details on GitLab's official documentation.
GitPlac has a instance-wide integration with Kubernetes, which enables execution of multiple parallel jobs. Every user can get access to virtually-unlimited amount of CI/CD resources.
Each user can add their own personal runners, be it on group or project level.
.exe file - but you normally can't use it in a CI/CD environment that is based on Linux (like the vast majority)
because it only supports building Windows executables in a Windows environment. cts/pyinstaller bypasses that requirement
by using Wine.