Okay, imagine you and your friends want to decide on what game to play. But there are different opinions on what game to play. Some friends want to play tag, while others want to play hide-and-seek.
To solve this problem, you all gather together and talk about the different games. You might talk about the rules of the games, what you like or don't like about them, and what would be fair for everyone to play.
This is kind of like what happened in the Synod of Ancyra. A long time ago, there were people who followed a religion called Christianity. But there were different opinions about what was true or not true about this religion.
So, a group of important people from this religion, including bishops and priests, gathered together at Ancyra (which was a city in what is now Turkey) to talk about what they believed and didn't believe about Christianity.
They talked about things like what the Bible (which is like a big book of stories and teachings for Christians) said about different topics, like God and Jesus. They also talked about rules for how people should behave if they were part of this religion.
Just like with your game decision, some people agreed on things while others disagreed. They argued and talked about different ideas. In the end, they came up with some decisions that they all agreed on.
These decisions were written down and became known as the canons of the Synod of Ancyra. They were kind of like rules or guidelines for how people should act and what they should believe if they were part of the Christian church.
So, the Synod of Ancyra was a meeting where important religious people gathered to talk about their beliefs and come up with decisions about what they would believe and do in the future.