Symmetric Key Encryption is a method of securing information where the same key is used for both encrypting and decrypting data. This means that both the sender and the receiver must have access to the same secret key to communicate securely. If someone else gets hold of this key, they can easily read the messages, so keeping the key safe is crucial. In this system, the process is fast and efficient, making it suitable for encrypting large amounts of data. Common examples of symmetric key algorithms include AES (Advanced Encryption Standard) and DES (Data Encryption Standard), which are widely used in various applications to protect sensitive information.