Let's say you're looking for your first job or internship in Hollywood but don't know exactly what you want to do. Development? Marketing? Production? They all sound interesting, so your plan is to apply to every job posting you find and see where you land. This is common and absolutely fine -- you should be trying out different aspects of the industry to figure out what you like best (or maybe you just need money and to find any job quickly, no judgment!).
But when you are applying for a wide variety of jobs, you shouldn't be using the same resume for every application. Different positions require different skills, so you'll want to alter your resume accordingly. Look at the skills each posting asks for, and find the experiences you've had in the past that match what's listed. You'll have much better luck in the job hunt if your resume is targeted and focused.