What is the difference between Resume and CV ?

The main difference between a resume and a CV is that a resume is short ( generally just one page ) and a CV is for the professional who has too many relevant experiences, awards, certifications, publications, etc.
A resume should not list every job you have ever had. If you are 40 years old, don't list the job you had at McDonald's back in the 80's.
However, if you are 40 years old but worked in the 80's as a professor's TA while working on your graduate degree(s), by all means, list that on your CV ! A resume is generally limited to the last 10 years but a cv lists all relevant experience, no matter the date. Put items in chronological order, but find ways to emphasize the most relevant experiences.
A CV is more detailed than a resume because the person with a CV has more experience, publications, presentations, etc.