Data encryption is a method of converting plain, readable data into encoded or scrambled data to make it unreadable by unauthorized individuals. Encryption is usually done using an algorithm and a key, which is a unique code that only the intended recipient possesses. Here is an overview of how data encryption works:

- The encryption process begins with the selection of an encryption algorithm, such as AES (Advanced Encryption Standard) or RSA (Rivest-Shamir-Adleman).
- A key is then generated by the algorithm, which is a random string of characters used to encrypt and decrypt the data. The length and complexity of the key depend on the algorithm used.
- The plain text data is then fed into the encryption algorithm, along with the key. The algorithm converts the plain text data into ciphertext, which is an unreadable form of the data.
- The ciphertext is then transmitted over a network or stored on a device.
- To decrypt the ciphertext, the receiver uses the same encryption algorithm and key to reverse the process. The receiver feeds the ciphertext and key into the algorithm, and it decrypts the ciphertext back into the original plain text data.

Encryption can be done at different levels, such as data at rest or data in motion. It is widely used to protect sensitive data such as financial information, medical records, and passwords from unauthorized access or theft. Encryption can be done using software, hardware, or a combination of both, depending on the application and the level of security required.