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.
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.