If the iMac is suppose to be secure from viruses, malware,spyware and other internet threats, then howcome i have seen internet security programs for the iMac?

Question

on the website it clearly stated "It’s highly secure and reliable"  and that "You don’t need to buy software to speed it up, keep it safe, or get it to work better."  and it also says that "The built-in defenses on a Mac help keep you safe from viruses and malware without the hassle of constant alerts and sweeps."   If this is the case, then howcome in download .com, i have seen internet security programs for the imac?
So if one day i accidentelly stumble across a website that has malware in it, will the imac protect me?
Theres this website that i feel to afraid to go to because some people reported a malware threat on that website. But will i be able to safely go to that website with the imacs security?
Im just confused that there are these internet security programs for the imac despite of the imacs built in security.

Answer 1

In addition to Kappy's excellent advice, you need to remember that only you can protect yourself (and your Mac) - for instance, I never go near any torrent site. Not only are most torrent downloads illegal, but quite a few softwares on those sites contain some not-so-nice additions (malware, etc). So, no, your Mac would not protect you there - you need to protect yourself; it is called "responsible websurfing".
I only download software from reputable sites (i.e. the developer); I don't go to questionable sites at all (there is a great plugin for Firefox called "WOT" - it grades the sites from excellent to "poor reputation") - if you use Safari, check to see if it is available there. And I don't download "free" software or music or whatever that costs elsewhere - I pay for it.
And, here is another article you might want to look at:
http://www.reedcorner.net/guides/macvirus/