Okay kiddo, so imagine you have a toy box full of different toys. Each toy is a different shape and color. Now, if I asked you to pick out all the toys that are blue, you would know which ones to look for and could separate them from the rest, right?
Well, that's sort of what an "a-un" is. It's a sound that you use to separate or distinguish different groups of things or concepts. In Japanese culture, an "a-un" is often used in Buddhist chants as a way to symbolize the beginning and end of something, or to represent the interconnectedness of different ideas or concepts.
So, just like you can use the color blue to group some of your toys together, you can use the sound "a-un" to group different ideas or concepts together in a special way. It helps us to understand the relationships between things and feel a sense of harmony and balance. Cool, right?