In many contexts, a resume is short (usually one page ), and so contains only experience directly relevant to a specific position. Many resumes contain keywords that potential employers are looking for, make heavy use of active verbs, and display content in a flattering manner.
If it's not, your resume and cover letter will not get a 2nd peek from any hiring manager.
The goal of your resume is to make an employer need to interview you. It's a strong promoting tool that promotes who you are, what you need to do, and the price you will bring to an organization.
A good resume should describe your professional experience, and your career accomplishments, training and education.
Often it is restricted to one to two pages with the exception of resumes for professional positions which require more in depth information about activities and experience related to that profession. During the past many "blue collar" roles only needed the job seeker to finish an application for work. Today virtually all bosses need both a resume and an application as well.
Your resume should represent your best capabilities honestly. It must be attention-grabbing, short and transient. The point of your resume is to get you in the door. Your resume should mirror what your capabilities are and what you can you can do.