Machine learning (ML) is the set of methods that let software improve its own performance on a task by learning statistical patterns from data, instead of being programmed with hand-written rules for every case. In an enterprise setting, this is the engine behind Netflix's recommendations, Capital One's credit-risk scores, Uber's ETA predictions, and PayPal's fraud scoring — systems that make millions of decisions a day without a human reviewing each one. 🧠 Understanding how ML systems are classified — supervised, unsupervised, semisupervised, reinforcement, batch, or online — is not academic trivia. It is the first architectural decision every ML platform team makes, because it determines what data you need, how you label it, how often you retrain, and how much it costs to run. Get this wrong at the design stage and teams end up building a batch-trained fraud model for a problem that needed online learning, discovering the mistake only after real losses. 🏗️ ...