Imagine you have a notebook where you write down stories or things that you have learned. Now, imagine that there are lots of other kids like you who also have their own notebooks with similar stories and learnings.
Sometimes, grown-ups who are really interested in what kids like you have to say, will come around and ask to see your notebook. When they see it, they might really like what you wrote and share it with other grown-ups who are also interested in learning from kids.
Now, imagine that there are so many notebooks and grown-ups that they need some way to organize all the notebooks and rank them by how much they like them. This way, other people who want to learn from kids can find the most liked notebooks more easily.
This process is kind of like journal ranking. Grown-ups who are interested in learning from researchers or academics will look at their notebooks, which are actually academic journals, to see what they have learned and discovered. Then, they will rank the academic journals based on how much they like what was written in them. This ranking helps other people, like researchers and academics, find the journals that are the best and most respected.