U.S. flag An official website of the United States government.

dot gov icon Official websites use .gov

A .gov website belongs to an official government organization in the United States.

https icon Secure websites use HTTPS

A small lock or https:// means you’ve safely connected to a .gov website. Share sensitive information only on official, secure websites.

Acknowledgements

Production Team

Troy Kitch: NOS Website Managing Editor and Developer, Writer, Graphic Design, Audio and Video Production

Marissa Anderson: Writer, Editor, Audio Production

Anna Gillis: Writer, Editor

Holly Kuzmitski: Writer, Editor

Education Content Team

Bruce Moravchik: Educator, Writer

Symone Barkley: Educator, Writer, Audio Production

Technical Consultation Team

Jennifer Coletta: Technical Support

Georgia Shao: Developer

Torie Ketcham: Developer