Encryption is the act of encoding data using algorithms to hide the real values in a way that allows you to decode the data at a later time, when it is needed. 

Oracle/MSSQL/MySQL Transparent Data Encryption: Transparent Data Encryption(TDE) is product specific and provides the ability to encrypt data in the database without the need for changes to the code or applications that access the data. 

Vormetric Data Security Platform: Simple one-stop, data-at-rest security. Vormetric offers TDE as well as many other Encryption and key management solutions. The platform offers a single management console to manage all encryption, key management and related security intelligence enterprise wide.