Aniconism in Christianity means that some Christians don't like using images or pictures to represent God, Jesus, or the saints. They believe that it's better to use things like words or symbols to help people understand God and Jesus, instead of relying on pictures.
This can be a bit confusing, because sometimes in churches you might see pictures of Jesus or saints, or even statues of them. But for aniconist Christians, those things aren't necessarily as important as other things like the words spoken during prayer or the symbols used during worship.
Aniconism in Christianity comes from a long tradition of debate and discussion about how to best represent God and Jesus. Some Christians believe that images can be a form of idol worship, or that they lead people to focus too much on the physical appearance of God and Jesus rather than their spiritual qualities. Others feel that images can be a helpful way to connect with God and remember important events and people from the Christian story.
Overall, aniconism in Christianity is a way of thinking about religion that emphasizes words and symbols over pictures and images. It's just one of many different ways that people can practice their faith, and each person has to decide what works best for them.