Apps can offer shortcuts for things you do frequently. You can use Siri to initiate these shortcuts with just your voice.
Some apps have Siri Shortcuts set up automatically. You can also create your own.
Tap Add to Siri when you see a suggestion for a shortcut, then follow the onscreen instructions to record a phrase of your choice that performs the shortcut.
You can also use the Shortcuts app to create a new shortcut that uses Siri, or to manage, re-record, and delete existing Siri Shortcuts. See the Tell Siri about yourself on iPad