In Java, == is used to compare whether two object references point to the exact same memory location. So, it checks for reference equality. On the other hand, .equals() is a method used to compare the actual contents or values inside the objects. For example, when comparing strings, == might return false even if the strings have the same characters because they are different objects. But .equals() will return true if the content matches. So, for object content comparison, we should use .equals(); for checking if two references are the same object, we use ==.