Encryption means encipherment - that is make secret, where as Encoding means to convert format, not necessarily securely.
Encoding is generally used in cryptography to mean that secrecy is not involved.
- The process of changing plaintext/string into ciphertext using a cryptographic algorithm and key.
- The (reversible) transformation of data by a cryptographic algorithm to produce ciphertext, which hide the data.
The words encryption and encipherment, both are used in same meaning.
After encryption, the resulting ciphertext should be indistinguishable from random data and it should be virtually not possible to get back the original plaintext without knowing the key. The strength of encryption depends on the cryptographic algorithm used and the length of the key.
Here encoding of the data takes place both before and after encryption.
In the .NET Framework, the classes in the System.Security.Cryptography namespace manage many details of cryptography.
When a new instance of one of the encryption algorithm classes is created, keys are autogenerated for ease of use. This is expained in another article.
The process of changing the format of the plaintext/string is called Encoding. Here no secrecy is maintained. By knowing the format which is used to encode the data,the encoded data can be decoded by any one.
So many times encoding the data alone is not adviced, to store passwords like data into the databse.
How encoding can be done by using c#.net is explained here: Encoding and Decoding