The Sofie system consists of several applications that work together (read more at Applications & Libraries).
Which applications to install depends a bit on what functionality you want.
Sofie with Google Spreadsheet support This installation allows you to use Sofie in its simplest form. Using Google spreadsheets to create rundowns and CasparCG to play videos and graphics, this is the quickest way to get started. Read the full article here: Installing Sofie with Google Spreadsheet support
Sofie with MOS / ENPS and MAM support This installation uses ENPS over the MOS protocol to ingest rundowns. It also uses the Media Manager to transfer media files and monitor media statuses. Read the full article here: (TODO: Article-to-be-written)