# Difference Between Encoding and Decoding

## Main Difference – Encoding vs. Decoding

In order to store or transfer information, it is often necessary to convert the information into a form that enables storage or transfer. This is especially the case when one needs to transfer or store data using digital means. The main difference between encoding and decoding is that the encoding is a process whereby information is converted into a form that is convenient for transfer and storage, whereas decoding is the conversion of encoded information back to a form that could be understood by humans.

## What is Encoding

In order to transfer or store information, it is often necessary to convert it into a form that is suitable for transferring/recording. Encoding is the process where information is converted into a different form. For example, every time you type a letter on the keyboard, it needs to be converted to a series of electric signals that the computer can understand. Under the widely used “ASCII” encoding system, the letter “A” gets converted to the binary signal 01000001 (in binary, this represents the number 65). In terms of the electric circuits, this is a series of signals: a 0 represents a low voltage and a 1 represents a high voltage.

An analog to digital converter (ADC) can be used to encode analog signals into digital ones. Music is a good example. If you record music through a microphone and send the data to a computer, the microphone is first taking in the sounds you produce as a continuous, analog signal. Then, the signal has to be converted to a digital form. To do this, the analog signal is sampled at a specific rate. Then, the sampled data is converted to a discrete value. To represent a discrete value, a series of 1’s and 0’s are used. The larger the number of 0’s and 1’s used to represent one piece of discrete data, the closer the digital data can be to the original, analog form.

### What is Decoding

Decoding involves reinterpreting the coded data into a form resembling the original form of data. For the example with music, this involves reading the music file and converting the binary data stored in the file (a series of 1’s and 0’s) into a series of electrical signals and eventually converting those signals into movements of a speaker, producing sound.

Music in a CD is encoded. Your stereo decodes this information and produces music.

Decoding is the reverse process of encoding, and for digital data, a digital to analog converter (DAC) has to be used to convert it back to an analog form.

The terms “encoding” and “decoding” are not limited to describing processes in electronics. The terms can also be used in a general sense: whenever an idea needs to be communicated, it needs to be “encoded” in a communicable form, such as speech. Upon receiving, the receiver has to “decode” the information. For example, a person who hears somebody’s speech will convert the speech into their own thoughts.

Information stored in our DNA is also a code. The sequence of nitrogen bases along a DNA strand carries information about how amino acids should be joined together to produce specific proteins. To decode this information, first it is transcribed into an mRNA molecule. Then, in a process called translation, a ribosome moves along the mRNA strand, decoding the sequence of nitrogen bases along the mRNA strand and joining up the correct amino acids to form the protein.

## Difference Between Encoding and Decoding

### Process

Encoding involves converting information into a form that is suitable for transferring or storing.

Decoding involves converting transferred/stored information back into a form that is understandable to humans.

Image Courtesy

“Flat view of a CD-R, with interference colours. Sorry about the dust fibres. Saved as JPG with IrfanView at 90% quality. Scanned by me with an HP ScanJet 4400c, and run through ACDSee’s “auto-level” filter.” by Ubern00b (Own work) [CC BY-SA 3.0], via Wikimedia Commons