You Have a Raspberry Pi. Now What? - Adventures in Raspberry Pi - page 6

MORE ABOUT OPERATING SYSTEMS
An operating system ( OS ) is a type of software that allows people to create,
store and manage files and applications that contain information on a computer.
Examples of popular operating systems include Microsoft Windows, Mac OS X
and Linux.
Linux is a free, open source operating system. This means that the program-
ming code it is made with is free and open for anyone to look at and possibly
improve on. There are many versions, or distributions, of the Linux operating
system available. Raspbian , the OS you use on the Raspberry Pi, is a Linux
distribution. You may have heard of some other well-known Linux distributions,
such as Ubuntu, Debian, or Fedora.
Raspbian was created by a community of thousands of volunteers world-wide. You
can connect to this community and learn more about Raspbian and Linux at www.
raspbian.org .
Preparing an SD Card to Store Your Software
A desktop or laptop computer uses a permanent storage device called a hard drive to
store information and applications. The Raspberry Pi doesn't have a hard drive, how-
ever, so your operating system, applications, and information all have to be stored on
a removable SD card. This type of storage, known as flash memory , is the same as the
kind you use with a digital camera to store all your photographs.
Before you plug in all the cables and so on, you first need to prepare (or flash ) an SD
card with the software the Raspberry Pi needs in order to run. This means that you
format your SD card and copy the free Raspbian OS onto it. If you don't do this step,
your Raspberry Pi won't recognise it as a storage device (like the hard drive of your
computer) from which you can boot software. Don't worry if these terms are unfamil-
iar to you—all will become clear as you read through this section.
The first thing a computer does when you turn it on is to start up, or boot , the
operating system.