Computer Security for Mac ( iMac ) ?.

Hi, This is my first Apple computer ( iMac OS Sierra 10.12.6 ) & my question is :- do I need to buy computer security for my iMac ? ( I used Norton on my old Windows Computer ), Some people say you don’t need it on a Mac others say put one on, I asked a guy at Stormfront ( Apple Store ) & he said you don’t need it providing you install Updates on a regular basis. What would you guy’s recommend ?.
John.

You don't need security software like that. I recommend using a couple of browser add-ons or extensions. One is Ghostery and the other is AdGuard AdBlocker, which you can get for Safari here, https://safari-extensions.apple.com, but they are available for almost all browsers.

keep your mac updated, use strong passwords (different difficult to guess password for every website you use), be careful what you click on and download, what websites you visit. avoid pirated software, download only from reputable websites like the apple app store.. avoid clicking on links in email (type the address in instead)... common sense and caution will go a long way.

You do not need to buy any security software like that for the Mac. There is a very limited amount of malware out there for Macs, and what is out there can be avoided by using common sense particularly avoiding pirated software, and not typing in your admin password to open a file that shouldn't require a password, such as an image file or a video.

You don't need to buy security for your iMac, turning on the firewall helps. It blocks unwanted incoming network connections. Make sure also to enable automatic updates, it helps to protect your computer including reacting to any emerging attacks to which your iMac might be vulnerable. And don't forget to use strong passwords for all your user accounts.

Many thanks for the replies much appreciated.
John.