CV (seen throughout the on-line application process) stands for Curriculum Vitae.  In short it really is the same thing as a resume.  If you have a formal document that gives a more comprehensive listing of professional history including every term of employment, academic credential, contribution or significant achievement, then please upload that document during the process when asked.  It's really just a fancy word that the programmers wouldn't let us delete for some reason.  Just ignore it.