Classification algorithms are a type of machine learning technique used to categorize data into predefined classes or labels. They analyze input data and learn patterns to make predictions about new, unseen data. Common examples include decision trees, support vector machines, and neural networks. These algorithms are widely used in various applications, such as spam detection in emails, image recognition in photos, and medical diagnosis in healthcare. By training on labeled datasets, classification algorithms can improve their accuracy over time, making them valuable tools for data analysis and decision-making.