An analogy is when we compare two things to each other, based on a relationship they share. So, for example, big is to small as old is to young, because the relationship is based on the fact that they are opposites.
The 11-Plus Non-Verbal Reasoning quizzes that follow each have ten analogies, which you must work out by deciding what is the relationship between the figures 1 and 2, and then applying that knowledge to find an analogy for figure 3 from the four choices you will be given. Sometimes the colour or shading will be your clue, and sometimes the angle or rotation will tell you what to look for.
An example has been done for you, with an explanation. Read it carefully as it explains in detail how to work out the answer. When you feel confident enough then you can begin the quiz. Be sure to study each picture carefully to spot the relationship - and good luck!