Commit Package
By committing a package changes made into it are stored into a commit repository, and depending on the deployment settings promoted and deployed automatically or manually to Runtime environments.
See also:
CONFIG_VALIDATIONS - Configure validation rules for commit messages
CONFIG_ISSUE_TRACK_SYSTEM - Configure linking to issue tracking system tickets
Usage
Give a commit message and commit a package in the Package Details tab:

Notes
Deployment settings are shown in the Designer main view under Environments and they can be modified in the Admin UI.