A one-page resume is appropriate for someone with limited work experience or looking for an entry-level job. However, someone with more in-depth professional background can use two pages to highlight relevant work accomplishments and education.
The premise of the one-page resume in all cases used to be more common, but as of 2014, that rule has changed. College students and recent graduates, for example, might choose to use a one-page resume due to minimal work experience. Alternately, for someone with 10 or more years of work experience, it's usually appropriate to expand a resume beyond a single page in order to encompass a career.