Though potential employers like to see who you have worked for and what positions you have held, the resume should not read like a history textbook. Since this is your primary marketing tool that will hopefully land you an interview, it is important to keep the content of the resume primarily focused on what you can bring to a company. Your past jobs might help you do this, so let them know that experience is a huge part of why you will be successful and include mention of experience that may be relevant to your new position.