Blue screen vs Green screen

As we are all working on our rotoscoping projects using green screen, I wanted to give a little more information on what blue screen and green screen do and what they differ in.

The obvious reason for choosing one or the other is the object or person in front. So if you are filming Kermit, you probably don't want to use green screen and if you are filming a Smurf (they're real), you probably don't want a blue screen,

i found this video below to be super helpful in further understanding the difference and learning more about why we should use one or the other and when.