Your time is usually structured by others.

You manage your own time.

You can count on parents and teachers to remind you of your responsibilities and to guide you in setting priorities.

You will be faced with a large number of moral and ethical decisions you have not had to face previously.  You must balance your responsibilities and set priorities

Each day you proceed from one class directly to another.

You often have hours between classes:  class times vary throughout the day and evening.

You spend 6 hours each day - 30 hours a week - in class.

You spend 12 to 16 hours each week in class.

Teachers carefully monitor class attendance.

Professors may not formally take roll, but they are still likely to know whether or not you attend.

Teachers check your completed homework.

Professors may not always check completed homework, but they will assume you can perform the same tasks on tests.

Teachers approach you if they believe you need assistance.

Professors are usually open and helpful, but most expect you to initiate contact if you need assistance.

Teachers often write information on the board to be copied  in your notes.

Professors may lecture nonstop, expecting you to identify the important points in your notes.  When professors write on the board, it may be to amplify the lecture, not to summarize it.  Good notes are a must.

Teachers often take time to remind you of assignments and due dates.

Professors expect you to read, save, and consult the course syllabus (outline); the syllabus spells out exactly what is expected of you, whit it is due, and how you will be graded.

You may study outside of class as little as 0 to 2 hours a week, and this may be mostly last-minute test preparation.

You need to study at least 2 to 3 hours outside of class for each hour of class.

You will usually be told in class what you needed to learn from assigned readings.

It's up to you to read and understand the assigned material; lectures and assignments proceed from the assumption that you've already done so.

Testing is frequent and covers small amounts of material.

Testing is usually infrequent and may be cumulative, covering large amounts of material.  You, not the professor, need to organize the material to prepare for the test.  A particular course may have only 2 or 3 tests in a semester.

Makeup tests are often available.

Makeup tests are seldom an option; if they are, you need to request them.

Consistently good homework grades may help raise your overall grade when test grades are low.

Grades on tests and major papers usually provide most of the course grade.

Initial test grades, especially when they are low, may not have adverse effect on your final grade.

Watch out for the first tests.  These are usually wake-up call to let you know what is expected - but they also may account for a substantial part of your course grade