Positive test cases and negative test cases

Question

what are positive test cases and negative test cases?

Upon googling about it i have found answers that are very confusing. Can anyone explain with

Answer 1

positive or negative is meaningless unless you put the requirement in the content. Let's say, one requirement is "the log in should fail if the user ID is not correct". I know it's bit counter-intuitive, a positive test is the type of test that will generate a failure in logging in, while the negative test will generate the result of successful log in.