Some classes offer more than on a section, i.e. choice of times, days and instructors.
For example, English 101 may have 12 sections, indicated by the different schedule number given to each section. Refer to the Schedule of Classes to choose classes that do not overlap. Do not choose two classes that meet during the same days and times. Do prior to registering. If you are taking a lab course check the time to make sure there is no time conflict.