Automation
In short: Automation is the independent execution of recurring tasks by software or machines.
In more detail: It saves time and reduces errors.
In Depth
Examples
Scripts (Bash, PowerShell, Python), schedules (cron), CI/CD pipelines, backups, macros in Excel, industrial robots.
Rule of thumb
Tasks you do by hand more than three times are often worth a script. Describe processes as a workflow. See DevOps.
See also: Workflow, CI/CD Pipeline, Bash, DevOps