Updated: Oct 5, 2020
Have your eyes glazed over already?
Don't worry, I'm really going to keep this simple.
To that end I'll answer the question before elaborating so you can decide if you care and want to read on :-)
The answer is "It depends".
Maybe not as useful an answer as you'd hoped but it is, I believe, a valid one.
VPN stands for "Virtual Private Network".
It is a mechanism for connecting your computer to some other network without exposing it to the broader internet.
It is analogous to taking a private tunnel between your house and your work versus walking the streets and taking the open-air/public risks to get to work.
VPNs have been widely used for a long time.
Often your workplace will require it if you are working remotely. They need you to securely and safely access their systems and sensitive data without the likelihood of it being intercepted or stolen on the way there and back. They'll also dictate what you can and can't do and see in their name i.e. while using their network and resources.
A lot of people have been using VPNs to pretend to be somewhere else in the world.
This is commonly done to access shopping, games and other geographically locked content i.e. If you want to watch that Netflix show that's only available in the USA, then you need to look like you are in the USA.
The geographical masking has been used to buy things from Amazon US (and the like) that aren't normally shipped outside America. Intermediaries are happy to take delivery and forward your stuff to you for a price. If this sounds suspect, then you're right. It's not a game I've bothered to play.
But these days VPNs are increasingly being touted as something you must have to be properly secure and safe on the internet.
VPNs for you and me create a secure tunnel to a trusted resource somewhere on the internet.
From that place you are protected from people knowing where you are and who you are...to a greater degree.
It's not perfect and you can still "leak" information regardless of where you appear to be, but it does make it nearly impossible for people to break into your computer from outside.
How "impossible" depends on your VPN provider and how good they are at their job.
Some antivirus products and web browsers now offer or include VPNs by deafult in some form or another.
They may offer you their own web browser which only accesses the web through their servers and filters out the bad stuff.
They may offer you a VPN like I've already described that you turn off and on as you feel the need.
It's worth finding out if you've got such a thing before you start spending more money on another subscription service.
NOTE: So called "Free VPNs" aren't really free. There's a price in there somewhere and that price may well be your privacy or your data or worse.
Like any software you acquire from the internet, make sure it is from a legitimate provider before you start playing.
In the past I've only used a VPN when I felt the need...and that wasn't very often.
But recently I felt the need to step up my security a bit and I am currently trialling full time use of a VPN.
If you are a frequent user of public wifi or other people's networks, then it really is a good idea to use a VPN. You never know what you are exposing yourself to on public wifi so a safe tunnel through it is pretty much mandatory these days.
Because what you are doing on the internet is going through this intermiediary/VPN provider, the speed at which they can deliver what you are after is important.
For example, you may be on a wonderful and high speed NBN connection (that's a bit of a joke by the way but stay with me) but if your VPN provider's servers can't handle all the data requests from all their users then you'll be frustrated...again.
If you have an Australian CHOICE membership, then I recommend you look at their VPN test results and advice. I'm currently trailling NordVPN.
VPNs aren't a silver bullet.
Much like antivirus software they are a layer of protection but NOT complete protection in of themselves.
Being on a VPN doesn't mean you can drop your guard or shelve other precautions you may be taking.
So do you need a VPN?
You tell me.