Common belief is that the difference between a curriculum vitae (CV) and a résumé (commonly written as resume) is that a CV is used in the UK while a resume is used in the US. While that is true, there is actually a small difference between the two documents. A resume is typically not more than a page long, and contains a summary of a person's relevant job experience and education. A curriculum vitae - which means "course of life" in Latin - is a longer document that includes details of important but relatively less relevant things, like a more detailed description of education, publications, awards, affiliations and other academic accomplishments.
Both are typically used to screen applicants, often followed by an interview, when seeking employment.
A resume is more focused on previous relevant work experience - employment history and key achievements in prior jobs. A CV, on the other hand, includes a summary of academic background as well as teaching and research experience, publications, presentations, awards, honors, affiliations and other details. Both CV and resume include the person's name, contact information, education, work experience and relevant work-related skills.
A resume is typically shorter than a CV - it is one or at most two pages long and needs to be concise enough to highlight the key aspects of your career.
A curriculum vitae is longer since it has more information. But nowadays, unless it's the norm in a specific country or a specific requirement for a job, CVs longer than two pages are also being frowned upon.
When to use a CV vs. a resume
In the U.S. a CV is used primarily when applying for international, academic, education, scientific or research positions or when applying for fellowships or grants. For most other jobs, a resume is the convention.
CV and Resume Writing Aids
A good resume is the doorway to a potential job, and regardless of how high the skill set or proficient the applicant, a resume that is not well-presented can cost one an interview opportunity. For candidates who are good at what they do but not great at presenting their skills well, there are professional resume writers, several websites and books that can help create custom-resumes tailored to suit the potential job.