It creates virtual storage drives where you can save your files.
Actually, one of these drives is just a regular protected file located in a directory inside the main hard drive, although all the information stored there will be encrypted and will require a password.
Additionally, you can install all the applications to which you want to limit access on these virtual drives.
Cryptainer’s free trial version lets you create a limited number of drives, with a maximum size of 25 megabytes and a 128-bit Blowfish encryption password. The full version improves on these features, but it’s not free.
Finally, you can encrypt any file and send it by e-mail. The recipient doesn’t need to have any software installed to access the file, just the encryption password.