What is a code (Informatics)?

It is a sequence of instructions that a programmer writes to solve a certain problem or to get a job done.
Indeed, computers did make the human life a lot easier by performing tasks very fast. When you use your phone or tablet, browse the web or use some software, the computer executes in the background a series of instructions in the background, (what you see is only the output of these instructions we call a program), Coding is writing in a certain programming language (C++/Python ...etc) that is a semi-language with few syntax rules to respect.