'What lifelong learning means?' isn't a question. It's four words with a question mark at the end.
For this to be a question, it has to be in a proper question form:
'What does lifelong learning mean?'.
And the answer? It means just what it says - carrying on learning things throughout your life. It can refer to adult education classes, or to professional training, or any other way that an adult might continue to develop their skills and expand their knowledge.