Some companies will indicate that they want you to submit a CV rather than a resume. A CV and a resume are not the same. CV stands for “curriculum vitae” and is meant to be an expansion of your resume. It is much longer than a resume, often three pages or more, and focuses mainly on your academic and professional accomplishments, with a particular focus on education.
Even if you are only sending in copies digitally, it is a good idea to print your resume (as it’s possible that hiring managers may be doing so) to be sure it prints on a single page, and is easy to read in printed form. Reading over a printed copy of your resume will also help you ensure that there is plenty of white space on the page and it looks professional.