Code is a language that a computer can understand. Although it doesn’t actually speak that language there is a little programme that will convert your code into a language your computer or micro-controller can understand.
Just as there are lots of languages in the world so there are lots of coding languages. They all communicate the same information, they just do it in different ways. All languages have their own vocabulary and structure. So too do the different coding languages.
The great thing is that with coding languages the vocabulary is very small and the structure is very consistent. Most popular coding languages are very similar.
If you are wondering which one to start with: that all depends what you want to do and what you are going to use. More on that next time.