Encoding is the process of transforming the format of information into a different format required for consumption by a different program or service. This can be compared to translating natural languages, like English or French, so that the other person can understand.
In computing, encoding is used to transform information from one program so that another program can process that information, such as changing unsafe ASCII characters in URLs to hexadecimal digits. You may have noticed that some characters in URLs get changed to a percentage ‘%’ sign followed by two digits, such as a space character being changed to ‘%20’.
Another example of encoding is compilers. Compilers change code written in one language to another language so that the computer or another program can understand and execute the code. For example, code written in the programming language Java will be compiled, or encoded, into Java byte code so that the Java Virtual Machine (another program) can execute the code and run the created program. Whereas the programming language C will be compiled into machine code which allows the computer to execute the created program.