Why use Antivirus:

• Your device stays functional and doesn't pose a threat to others

• Your device doesn't overload the network

• You keep your stuff safe

macOS

Again, very similar to windows. Many tools used for windows have a mac version 

• Malwarebytes is a free antivirus that works for Mac too

• Scan your system with an antivirus at least every month, but preferably every day (it will do it automatically). 

• CCleaner for Mac is also available.

The school uses an email protection system called Egress that scans every email sent from outside the school network 

(any email that doesn't end in @oundleschool.org.uk).

Phishing is a method of stealing your usernames and passwords by tricking you into entering your passwords into fake websites. They can create websites that look identical to the Facebook, Snapchat, Google login pages along with many other sites. They often will send a message to someone with a message similar to "Have you seen this video!?" or "Are these photos yours?!" in order to intrigue you. This message will be accompanied by the link to their fake website. This will make it appear that you have to login in order to see the links content and if you do, you are giving them access to your whole account. This means that they will often log into your account and send similar messages to your friends. Your friends are then more likely to believe the fake link as it came from a "trustworthy" source (you). This creates a chain reaction where the phisher can gain lots of passwords and details in a very short amount of time. 

Free VPNs are a bad idea. They're unnecessary and dangerous, the way they make money is to take as much data from your computer as possible and sell it to the highest bidder, this can include passwords and credit card details. Fortunately,  they don't do it to every computer every time they're used, so chances are if you've only used one once, you're probably safe but it's still not worth the risk.