Encryption is known to be a two-way function, which means that even if the data is already encrypted, there is a possibility that it will be decrypted with the use of the proper key. Hashing is another method that can be used in order to protect data, but this time, this will make sure that text will be mixed up together so that there will be a unique message that will become available.
If the algorithm is properly created, you can expect that the algorithm cannot be changed anymore. It will be hard to reveal what the password used to be if hashing would be used to protect it.