what is very important to learn in CSS for begginers?

[powerup]

in CSS we define the colors and sizes in "styles".Then as we write our documents you refer to the styles.Therfore:if you change a certain style it will change the look of our entire site.

mr/mrs

what are so much important to learn in this topic for preparing qiuz exams by multiple choices?

[abz]

im a little confused by this. But as far as I gather, you have an exam on CSS and want to know what you should revise???

If this is the case, just go over your sylabus, your notes, ask your teacher/lecturer for guidance if you need it; thats is what they are there for.