Downloading the Raspbian Stretch image 

We now have to download an OS to run on our Raspberry Pi. While there are many third-party Raspberry Pi OSes available, we will install Raspbian OS. This OS is based on Debian and is developed specifically for the Raspberry Pi. The newest version is called Raspbian Stretch.

To download the Raspbian Stretch image, visit https://www.raspberrypi.org/downloads/raspbian/, look for the RASPBIAN STRETCH WITH DESKTOP ZIP file, and click on the Download ZIP button, as shown in the following screenshot:

Now that we have a copy of Raspbian Stretch on our laptops, let's move on to writing it to our microSD cards.