Encryption is a method of using an algorithm to encrypt data so that it is unusable by third parties. Only by using the right key -a secret password- can the original data be decrypted again.
Encrypting your laptop's hard disk (system drive) is mandatory.
Encryption of files and folders or volumes, including for internal and external cloud storage, also for e-mail attachments when the e-mail message itself is not encrypted.
Quickly encrypt one or a few files: symmetric encryption (password-based).
NOTE: It is very important to remember your password because you will need it to access your encrypted data.
Container encryption: creating an encrypted file container or encrypting an external (physical) hard disk or USB stick
Digital signature and encryption of e-mail messages with public key cryptography