It is customary to write a small program first, before making larger programs. A small program, with its only task being the display of a text message, saying "Hello, world", is often used. Such a program can be referred to as a Hello world program.
A Hello world program written in Python is shown in Figure 1.
print "Hello, world"
Figure 1. A hello world program in Python.
The program in Figure 1 contains only one line. This line is a print statement, saying that the string "Hello, world" shall be printed.