Passports & Travel Documents: Needed?

At Disney Cruising Group, on the subject of passports, we defer to to the official Government Agency site links:

Passport: Difference between passport book and passport card (includes cost/prices)
https://travel.state.gov/content/passports/en/passports/information/card.html

To apply for a passport: https://travel.state.gov/content/passports/en/passports/applyinperson.html

Renew a passport: https://travel.state.gov/content/passports/en/passports/renew.html

Below is the official Disney Cruise Line page regarding Travel Documentation:
https://disneycruise.disney.go.com/faq/preparing-for-cruise/travel-documents/