Chances are, if you applied to the University of Chicago, you know a thing or two about this "Core" that everyone keeps talking about.
In its original conception, the Core was supposed to focus on a canon of classic texts, and class time was meant to be spent using Socratic-method discussion to understand primary sources—rather than text books and lectures. The idea was that you probably shouldn't be able to call yourself a U of C alum if you hadn't thoroughly struggled through the Iliad or Rousseau's Social Contract.
Today's Core resembles more of a glorified system of what other colleges call gen ed requirements. While many of the hard-line traditionalists on campus grumble that the Core of the 21st century has strayed too far from former President Robert Maynard Hutchins' original vision, some more progressive professors argue that students shouldn't solely read texts from dead white guys.
In short, the core is composed of the following subjects: civilization studies ("Civ" or history), humanities ("Hum", pronounced "hume"), arts, natural sciences ("nat sci"), physical sciences ("phy sci," double rhyming with "high"), biological sciences ("bio"), mathematical sciences ("stat" or "calc"), and social sciences ("Sosc," rhyming with gauche). While students are also required to fulfill language competency and fitness requirements, these areas are not considered part of the Core.
The backbone of the Core is still in the humanities and social sciences. These courses are generally more challenging than the biological and physical science courses and often feature some of the University's superstar professors. Also, A.P. and O-Week test credits can let students skip science and math classes, but Hum and Sosc are still required.
The sciences have been subject to attack, especially classes like Core bio for students who didn't take A.P. biology in high school. Chief complaints are the heavy writing load that many say seems unreasonable for a science class and the relatively superficial depth of material, as compared to Hum and Sosc classes.
Because students can't opt out of humanities or social sciences, these classes end up defining a large part of the first-year experience. Students are generally introduced to the "that kid" in their Sosc class, the fellow we all love to hate. During the first lecture, some bright-eyed scholar will raise his hand to answer a question and embark on a mini-treatise peppered with lots of pretentious language as the rest of the class groans and rolls their eyes. (Still, don't be surprised to find that the "that guy" who sat next to you in Sosc ends up still being a good friend three years later.)
The University has recently started pushing students to complete these requirements earlier, with the idea that the Core should precede the other two parts of the U of C curriculum: classes for the major and electives. Under a reverse seniority system, fourth-years trying to squeeze in their procrastinated Civ requirement before they graduate will soon be surprised to see that the first-years get preference over them for the class.