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No, I would say reputation is like level - you grow with a time because you comment, post articles etc.
But karma is something like - the attitude of others towards you. If you have been rude to someone the whole day they can vote for to downgrade your karma and because of that some of your options will be locked. In steemit it could be less earning or for example inability to write comments or post articles.

Steemit reputation is based on how people vote for you. It can be destroyed by flagging. You don't gain any extra privileges for a higher rep, but maybe you should. If low rep accounts couldn't post as much it would reduce the spam.

Agreed, it was not the best example to compare reputation and level, since level usually can't be downgraded, but yea, either reputation should have more abilities or there should be implemented another quality for a user which would decrease spam.