The terms "resume" and "CV" have very similar meanings and are sometimes used interchangeably. In the United States, a "resume" is a document that is often not much longer than one page. Each time a person applies for a job, his or her resume should be tailored in order to reflect skills and experience that will be of particular use in that position. For example, if a person were to simultaneously apply for a jobs as a biology teacher and a biking tour guide, he or she would likely highlight different professional and academic qualifications in each resume.
A CV is longer than a resume and includes a complete listing of a person's professional history. A CV should include, every position that a person has ever held, a comprehensive list of academic credentials, as well as information on publications and other significant achievements. In some cases, CVs are many pages long. In general, CVs are required when applying for positions in the medical and academic field. Resumes, on the other hand, are preferred when applying for business position
(source: wisegeek.com)