== — reference comparison (same memory address?). equals() — content comparison (same data?).Vivid analogy: Two identical cars. == asks "Is this the exact same car?" (No — different VINs). .equals() asks "Are these cars identical in features?" (Yes — same model, color, engine).Why it matters: The String pool makes == work sometimes, creating a trap. Code using == for Strings may pass tests but fail in production when objects come from different sources.javaString s1 = "hello";String s2 = "hello";s1 == s2; // true — String pool optimizations1.equals(s2); // true — same contentString s3 = new String("hello");s1 == s3; // false — different objectss1.equals(s3); // true — same contentString userInput = getUserInput(); // NOT from poolif (userInput.equals("exit")) { // CORRECT System.exit(0);}// if (userInput == "exit") { // WRONG — may fail!- == — null checks and reference identity.- equals() — content/value comparison.