What is a computer virus?:
Computer code that can copy itself and can lead to a corrupted system or destroyed data.
What is malware?:
Software that interrupts day to day usage of the computer, collects information: such as credit card numbers, passwords, etc. , can pop ads.
What is Ransomeware?:
Software that blocks access to a computer until money is paid.
What is Man in the Middle?:
"In its simplest form, the attack requires only that the attacker place himself between two parties that are trying to communicate and that he be able to intercept the messages being sent and further have the ability to impersonate at least one of the parties."
https://blog.kaspersky.com/man-in-the-middle-attack/1613/
What is a firewall:
Software that prevents unauthorized access to or from a private network
Malware Protection Software:
Software that prevents, detects and removes malicious programming on individual computers.
Virus Protection Software:
Detects and destroys computer viruses
A word of Free Virus Protection:
I read the reports put out by SE Labs https://selabs.uk/en/reports/consumers.
AV-Comparatives https://www.av-comparatives.org/
AV-Test https://www.av-test.org/en/
Avast has been popular among people but I have major issues with it. Did you know the free one on default has a setting that injects your email with a signature saying it has been protected and scanned by avast. That could be exploited. I use to use AVAST until they did the signature injection. Avast is resource heavy and has interfered with being able to play some games. While free Virus protection is available, it is not necessarily the best option. Research your choice. See how it performs in the reports. Read reviews of the current version because they change from year to year.
Why I use a premium virus protection:
I use Bitdefender Antivirus Plus. After AVAST failing to meet my standards I went looking for a Virus Protection that meet them. My standards are: Not Resource Heavy, and Does well on virus protection. It was between Bitdefender or Kaspersky. Those two are top Virus Protection right now. Paying for virus protection is something I don't mind doing. I've been using it for a year now. It also blocks malicious web ads. It has worked for me. It doesn't cost that much as it's on a year basis.
Free Malware Protection:
Malwarebytes is what I used for free for awhile. The free one is just as good as the premium version you just have to manually update it everyday. It's protected from malware on a number of occasions from sites that have been safe in the past.
You need a good virus protection software combined with a good malware protection software to protect your pc. For me that's Bitdefender and Malwarebytes. Do your homework and research what you want to use.