What is symmetric encryption?

Symmetric encryption is a type of encryption where the same key is used to encrypt and decrypt the message. It's called "symmetric" because the key used for encryption is identical to the key used for decryption. The data, or plaintext, is transformed into ciphertext during encryption, and then the same key is used to revert the ciphertext back to plaintext during decryption. It is a straightforward method but requires secure handling and exchange of the encryption key.