What is VeraCrypt?
VeraCrypt is a free open-source disk encryption software for Windows, Mac OSX and Linux.
Why encrypt?
Protect your data from unauthorized access.
It could be a security policy for the company you work for if you are handling confidential data.
If you are an activist or hacktivist and you want to protect yourself, you can encrypt your C drive so your browsing data/history cookies etc is encrypted.
Isolation of particular files, example malware ransomware etc.
Encrypted file containers can be transferred: example, encrypting your backups and uploading them to the cloud
Key points to take:
Encryption and decryption require quite a bit of CPU processing power, so depending on your system specs and the size of the drive and the files you are encrypting or decrypting it can be time-consuming.
If you encrypt drives/files that are constantly being read and written so they can take longer to load and save as the files are constantly being encrypted or decrypted.
So in essence encryption can cause slowdowns, if you encrypt the main system drive (the drive in which the OS is installed).
So I would not recommend encrypting the C/system drive.
What you can do with Veracrypt
Allows you to create a virtual encrypted disk within a file and mounts it as a real disk.
Allows you to Encrypt an entire partition or storage device such as USB flash drive or hard drive.
Encrypts a partition or drive where Windows is installed (pre-boot authentication).
Encryption is automatic, real-time(on-the-fly) and transparent.
Parallelization and pipelining allow data to be read and written as fast as if the drive was not encrypted.
Encryption can be hardware-accelerated on modern processors.
VeraCrypt adds enhanced security to the algorithms used for system and partitions encryption making it immune to new developments in brute-force attacks.