Each day you proceed from one class directly to another. Teachers carefully monitor class attendance. Professors may not formally take roll, but they likely know if you attended. Most of your classes are arranged for you. You arrange your own schedule in consultation with your academic adviser.
Schedules look lighter than they really are.
Professors Teachers approach you if they believe you need assistance. Professors are usually open and helpful, but most expect you to ask if you need assistance. Teachers provide you with information you missed when you were absent. Professors expect you to get from classmates any notes from classes you missed. Teachers present material to help you understand the material in the textbook.