1) i often hear people talk about spamming and scamming, is there a difference or the two of these are alike?
Spam is for instance unwanted mail that is sent to your email account, or else posts made on forums by people who are not real members and have no intention of being part of your community. Scams are things that you get taken in by.
2) what exactly means "spam"?
See above.
3) what is the problem with spam?
It frequently contains graphic images that are unsuitable for minors.
4)what are ISP's doing about spam and what can i do about it?
They aren't doing a whole lot, but for your forums you can use things like captcha to try and keep them out. For email, report any offending mails to your provider (there will be a button to do this).
5)what is government doing about spam?
From the US it is illegal, but they can't stop it from elsewhere.
6)Is there any efficient way, if anyone knows, to reduce spam to its minimum?
Not really-its a battle that has been fought for years.