Encryption is making information unreadable to those who do not have the right "key" to unlock it. Without the key, even if someone gets hold of your documents, they will just appear as nonsense. There are many ways to encrypt your documents using a range of different software packages. If you are using a Windows based PC, Windows 10 Pro and Enterprise versions come with BitLocker which can be used to encrypt your whole hard disk. As pointed out above, you can also encrypt selected folders in Windows, which also uses BitLocker. You will need to make some choices about how you want to unencrypt your information: Obviously, when you want to access your documents, you want them to be understandable again, so you need to create a key to unlock your data. Some modern PCs have a TPM chip, which will store your key for you - this means that anyone trying to access your documents from anywhere else (someone gaining access to your WiFi for example) will not be able to, but if someone were to get access to your actual computer they could still access your documents. So, as well as using a TPM chip, which is good practice if you have one, you can also setup either an additional password to use when you turn on your computer or, as I prefer, use a USB key. You can use any USB drive for this, and it simply needs to be inserted into a USB port when the computer is turned on. Once the computer is up and running, the USB key can be removed and should not be stored with the computer. There is a useful guide to BitLocker here: https://www.windowscentral.com/how-use-bitlocker-encryption-windows-10 but this is only one of many tools that you can choose from. Your anti-virus / anti-malware software may include drive encryption if you do not have a version of Windows that includes BitLocker.