What does "side doors automatic" mean?

When selector placed to automatic, if doors are open, evacuation slides would deploy -

If selector in manual, evacuation slides do not deploy if door is opened -

Doors must be in manual to permit normal door opening at airports -

Doors are placed in automatic when taxiing for takeoff, until arrival after landing -

Generally that command is not given by a pilot, but the senior flight attendant -

Upon arrival after landing, command will be "cabin door selector in manual" -

Often this is heard in combination with the phrase "Crosscheck". (e.g. "Cabin crew, doors to automatic and crosscheck.") This is an instruction to switch the doors of the aircraft from "manual" to "automatic". When in "manual", the evacuation slides will not deploy when the doors are opened. However, in "automatic", the evacuation slides will deploy upon the opening of the doors.

they open automatically