A disclaimer clause is a statement that says you're not responsible for certain things. For example, in a fitness app, there might be a clause that says the app isn't a substitute for professional medical advice. It means the app doesn't replace a doctor's advice. This protects the app maker from legal trouble if someone relies on the app instead of going to a doctor. So, a disclaimer clause is like a warning to users about what the product or service can and can't do.