Encryption is the process of converting information or data into a code to prevent unauthorized access. It uses algorithms to transform readable data (plaintext) into an unreadable format (ciphertext) that can only be reverted to its original form by someone with the correct decryption key. This technique is widely used to secure sensitive information, such as personal data, financial transactions, and communications. Overall, encryption plays a crucial role in ensuring data privacy and security in the digital age.