Why Do We Use Programming Languages?

A student asked the following in the Q&A section of my "Software Development from A to Z" course:

"I'd love to know more about where other programming languages and frameworks fit into the software development lifecycle, including Python, C/C++, Ruby, etc. and why they are used."

Answer:

I'm going to quote from my book "The Non-Programmer's Programming Book: Programming Foundations for Absolute Beginners. Learn to code from scratch with no prior experience."

"Coding or programming is telling a computer what to do. It works by typing commands in a specific order.

Every computer program consists of sequences of commands. Your mail app, the web browser, Facebook, WhatsApp, the games on your phone - each of them is a set of instructions. These instructions tell the computer to perform specific tasks, like multiplying two numbers, opening a file or making your computer beep."

In essence, "programming is giving directions to computers in the form of sequences of instructions. We provide these instructions using programming languages. When we say programming language, we usually refer to high-level programming languages like Python, Swift, C++, Java, or C#.

Each programming language consists of a set of keywords and some rules for instructing the computer what to do. It’s like the vocabulary and the grammatical rules in the case of human languages."

The implementation part of the software development process is where we use programming languages, libraries, and frameworks to build the actual software system. We pick different languages depending on various factors. You may consider the target operating system, the type of the system we develop, the available technology stack, to name a few.

For example, JavaScript is useful if you want to develop a website, but it wouldn't be a wise choice if we aim to create a real-time operating system.