Data collection in data science can be classified into structured, semi-structured, and unstructured data collection. Structured data comes from databases and spreadsheets, while unstructured data includes text, images, audio, and video. Semi-structured data includes JSON and XML formats. Data scientists use different tools and techniques such as web scraping, APIs, sensors, data collection strategies in data science and surveys to collect data efficiently. Choosing the right data type and collection method ensures better model performance, accurate analytics, and meaningful insights.