If said in a sentence, Unicode is an encoding standard. If the working of the computer is understood, then we will know that computers do all their work based on binary digits (0 and 1) and their calculations. It is also the main language of computer which is also known as machine language.
Later they are converted into different number systems through Calculations like Octal, Decimal and finally Hexadecimal and finally Hexadecimal numbers together form a special group like ‘1FFF’ which is converted by Unicode and shown as a word or Symbol. And this process of converting is called Encoding.
If you are connected to the technology in any way (through mobile, computer etc.) then you also use Unicode as it has now become a standard.