Imagine that you're sitting in front of a big pile of different flavored candies. You really like one particular flavor, like strawberry, and you want to have more and more of it. In music, there's something similar called a "predominant chord," which is like the strawberry candy of a song - it's the chord that the song seems to revolve around and it just feels good to your ears.
Now, let's say you're listening to a song and it has three chords: A, D and G. The G chord is the predominant chord because it's played more often than the other chords, and it creates a sense of tension and release that brings a pleasing sound to your ears. The G chord is like the strawberry candy that you have the most of and keeps you happy while eating other candies.
So, a predominant chord in a song is like a central candy flavor that stands out more than the others, and makes the song sound good and enjoyable to listen to.