I can see your answer. I would guess that it was deleted because it was not a very good answer, it was just a link to a Wikipedia page with no additional commentary, insight, or discussion.
Posting a simple link with "read this link" is OK as a comment, but the threshold is higher if you want to post an answer. Try to add something useful to the link you post. If you're going to link to a long Wikipedia entry, at least try to point out the sections that will be useful to the Original Poster and why (although that still might get downvoted as not being very useful).
I would rather comment but if I don't have 50 reputation points I can't. so what can I do? Should I really copy/paste wiki next time?
I understand that is frustrating. I can't speak for the exact reason that you can post an answer right away when you join the community, but you need 50 rep points to post a comment, though I would guess it's to discourage people from joining and immediately posting low-quality comments.
But no, please do not copy & paste a wiki page next time. You are welcome to copy sections of text and indicate their origin on a wiki page, and then add your own comments or insights on that text to make a useful answer...