Programming languages are what we use to tell computers what to do.

Computers talk to one another in binary, which looks like this:

0011101010101111000111

It doesn’t make sense to me or you, but it sure does to your computer!

Since we can’t write in binary, we need to write our instructions in a programming language. They usually look like weird English with a lot of semicolons and extra parentheses. Then a program called a compiler or interpreter converts our instructions into binary that the computer can understand.

There are hundreds of different programming languages, and they all make you type different things to get the same result. When you write your first program, it’s traditional to make the computer print “Hello world” on the screen – take a look at how you do it in these four different languages:

C++

#include <iostream> using namespace std; int main () { cout << 'Hello World!'; return 0; }

PHP

echo 'Hello World!';

Ruby

puts 'Hello World!'

Java

class helloworld {
    public static void main(String[] args) {
         System.out.println("Hello World!");
    }
}

No programming language is really better than another – they all have different strengths and weaknesses. Some might be faster, or better in robots, or really good at making web pages. PHP, Ruby, and Python are three popular programming languages for the Web.

Cocktail Party Fact

Up until the mid-1980’s, computer programs were written on cards with holes punched in them (punch cards). If we still used them today, a single iPhone picture would take up over 9,000 punch cards!