The Common Application, or the Common app, makes applying to College so much easier. Basically it's a College admissions application that can be used and submitted to 315 various Colleges throughout the country. A neat idea that saves prospective students from filling out handfuls of College applications.
It all makes a lot of sense really, as most applications pretty much ask and require the same information. However, often colleges will have supplemental applications that an applicant must fill out along with the Common App to be considered for admission. Still, its a valuable tool that means less time spent on the busywork of applying for admission.