"never" and "nevertheless"

What does the words never and nevertheless mean?
Does they have any relation between them?
Explain me with examples.

Also correct my mistakes in this question.

I have never done this before.
I have never scored 100 %t at the exam.
I have never scored 100 % at the exam; nevertheless, I was still the best student in my class.

These are two different words with different meaning. Use a dict, Arun.

[b]nev·er /b

  1. Not ever; on no occasion; at no time: He had never been there before. You never can be sure.
  2. Not at all; in no way; absolutely not: Never fear. That will never do.

nevertheless - In spite of that; nonetheless; however: a small, nevertheless fatal error.
despite anything to the contrary (usually following a concession); “although I’m a little afraid, however I’d like to try it”; “while we disliked each other, nevertheless we agreed”; “he was a stern yet fair master”; “granted that it is dangerous, all the same I still want to go”


I have underlined some comments inserted into your message:

In spite of his illness, he went to school.
Can I use nevertheless in this sentence as,
Nevertheless his illness, he went to school

Which one is appropriate:
Please explain to me with examples
Please explain it to me with examples

It would be very kind of you, if you mention my mistakes in this message.

No, that is not correct. You could use “nevertheless” like “in spite of that”, though it is not precisely the same. In this sentence you have only “in spite of”: you cannot replace that with “nevertheless”.
Example: “He was ill. Nevertheless, he went to school.”

This is correct. The word “it” may be left out here, although it is even better and more complete with “it”.

This is even better.