Okay kiddo, so let's start with what a saint is. A saint is someone who lived a good life and did good things for others, and so people believe they are special in a spiritual or religious way.
Now, symbology means using pictures or symbols to represent something. So when we talk about saint symbology, we mean the different pictures or symbols that are used to represent each saint.
For example, St. Francis of Assisi is often shown in pictures with birds and other animals because he loved animals and took care of them. St. Jude is usually shown holding a medal or wearing a necklace with the image of Jesus on it because he is the patron saint of hopeless causes and people pray to him for miracles.
Each saint has their own story and the symbols we use to represent them help us remember what they did and how important they were to people. Does that make sense, kiddo?