What are some ways to decrypt a password from an encrypted one?

Normally passwords are not typically encrypted; hashed with a one-way function would be the right word. By "One-way," it means they can’t be decrypted or can be reversed.

• For authentication of a website, the user enters a password, it gets hashed again, and the output is compared to the hash code which is already being stored.
• If both the hash code matches, you are allowed in, so the only way is to guess a password, hash it and compare the result.