A resume is the preferred application document in the US and Canada. Americans and Canadians would only use a CV when applying for a job abroad or if searching for an academic or research oriented position.
In the UK, Ireland and New Zealand, a CV is used in all contexts and resumes aren’t used at all. The CV prevails in mainland Europe and there is even a European Union CV format available for download.
In Germany, the CV is more commonly known as a Lebenslauf (true to the latin origins) and is only one of many application document the poor German job seekers must produce to get an interview.
In Australia, India and South Africa, the terms resume and CV are used interchangeably. The term resume is used more for jobs in the private sector and CV is more commonplace when applying for public service positions.