In the United States, is a CV the same thing as a resume?

No. In the US, a resume is the short document used for most jobs, usually one or two pages, while a CV is a longer, detailed record used mainly for academic, research, scientific and medical positions. If a US job advert just says "submit your resume", send a resume, not a long CV.

Key differences:

• Resume: tailored to each job, focused on relevant achievements, one to two pages.
• CV: complete record of education, publications, grants, teaching and presentations; can run many pages.

If you come from a country where "CV" means the everyday job document, call it a resume for US applications and cut it to resume length.

Some US employers outside academia, such as international organisations or hospitals, still use the word "CV" in adverts. When in doubt, read what the advert asks for: if it lists publications or research, send a CV; if it asks for a summary of experience and skills, send a resume.