As you could see during the RPI introduction, you have several OS that can be installed on a RPI. As we have class 4 SDCARDs, it takes too much time to install a full image on it.

You can download a lightweight install that will download the extra packages from the internet. Download the following file:

https://github.com/hifi/raspbian-ua-netinst

Extract the content of the archive and copy it to the SDCARD. Once completed, you can insert it in your RPI. Complete your User guide with this possible install step.