What does Decoding mean?
Decoding is the process of converting code into plain text or any format that is useful for subsequent processes. Decoding is the reverse of encoding. It converts encoded data communication transmissions and files to their original states.
Techopedia explains Decoding
Most computers use an encoding methodology to transfer, save or use data. Data to be encoded are transformed via an encoding mechanism (for example, the American Standard Code for Information Interchange (ASCII) or BinHex) and transmitted via a communication medium.
As an example, when sending an email, all data, including certain attachments and images, are encoded using a format such as Multipurpose Internet Mail Extensions (MIME). When data arrives, decoding converts the email message content to its original form.