What is the difference between == and .equals() in Java? == checks for reference equality, meaning it compares memory addresses. equals() checks for value equality, which can be overridden in user-defined classes. By default, Object’s equals() method behaves like ==. In the case of Strings, == compares references, while equals() compares actual content. For example, new String("hello") == new String("hello") returns false. However, "hello".equals("hello") returns true. Wrapper classes like Integer use caching for small values (-128 to 127), affecting == behavior. Misuse of == instead of equals() in objects can lead to logical errors. When should you override equals(), and what other methods should you override alongside it?