To encrypt information is to make sure that you keep that information confidential, and that integrity of this information remains when encryption is removed.

In other words, encryption enables you to share something in secret, and whoever gets that secret and is able to open it, will be able to verify its authenticity, that indeed it was created by you.

Symmetric encryption uses the same key to encrypt and to decrypt data, whereas asymmetric uses a key pair, where one is public and another is private key; one is used for encryption as one is used for decryption.

Although asymmetric encryption tends to be quite a bit slower in terms of processor needs, it is often preferred for security.