A curriculum vitae, or CV as it is commonly known, is the term used for an academic résumé. Although a CV is similar to a standard résumé in some respects, the two are also very different from each other. The Latin phrase curriculum vitae means "the course of a life," and the structure of the CV reflects this definition. In a CV you are detailing the course of your academic life: which universities you have attended, what you have accomplished (research, teaching, presentations, service, awards, etc.), what academic experiences you have gained, and more. You should refrain from listing anything unrelated to your academic work in your CV. For example, CVs do not contain a section for "career objectives," which can sometimes be found in other kinds of résumés, nor do they list non-academic employment or credentials (unless they are relevant to your academic career).
CVs are essential when applying for academic jobs or grants, and they are usually necessary pieces of award nominations as well. It is a good idea, then, to begin compiling your CV from the moment you begin graduate school. Spend a bit of time at the end of each semester updating and revising your CV. Doing so will make the sometimes daunting prospect of putting together one's CV a lot easier in the end.