Raspbian Installation - Step 1 - Download NOOBS
In order to make the Raspberry Pi board work, an Operating System needs to be installed on it. For people who are new to the world of Pi boards, NOOBS (New Out of Box Software) makes is very easy to install one of your choice. You can either buy an SD card pre-loaded with NOOBS or download one from https://www.raspberrypi.org/downloads/noobs/ as a first step