The role of artificial neural networks (ANNs) in machine learning is to model complex patterns in data, enabling predictive and classification tasks. ANNs are inspired by biological neural networks and consist of interconnected nodes (neurons) that process information through weighted connections. They excel in recognizing patterns and features in large datasets, making them useful for applications such as image recognition, natural language processing, and voice recognition. By training on labeled data, ANNs learn to adjust their weights, improving accuracy and performance over time. Their versatility and effectiveness make them fundamental in advanced machine learning solutions.