Docker exec command enables troubleshooting inside running containers

The docker exec command allows developers to access a running Docker container to execute commands and diagnose issues. It can open an interactive shell inside the container, enabling inspection of the filesystem, processes, and environment variables. This tool is useful for troubleshooting problems like configuration errors or connectivity issues without stopping the application. Users must first identify their target container using 'docker ps' and then use 'docker exec -it <container> /bin/bash' to gain access.