In the United States, a CV is almost exclusively limited to professions in academia, science and medicine. In the case of academia, the main focus of the CV should be to identify yourself as a scholar. The added length, should be filled with proof of your skills as a teacher, scholar, and your knowledge of education. A CV should be thought of as a living document, and it will change frequently based on the updates in your education and career.
Only include your GPA if it is higher than 3.5 on a 4 point scale (no need to mention that 2.0 when you moved into the frat house sophomore year) and only if you are a recent graudate. There are a few exceptions to this rule, like if you’re applying for a job in academia or engineering where a GPA is expected. You can also list honors or awards if you’re a recent graduate. If you attended college, but did not finish your degree, list the number of credits obtained. For recent graduates, education and internship are your main selling point. But if you’ve already been in the workforce, tone down your education section, the best rule of thumb is that one line will suffice.