PlayStation Network

PlayStation Network is a digital media entertainment service provided by Sony Interactive Entertainment. It was launched on November 2006 initially for PlayStation consoles only, but eventually expanded to encompass smartphones, tablets, Blu-ray players, and high-definition televisions. It has 110 million members as of April 2016, 70 million of which are active monthly.

PlayStation Network's services are dedicated to an online marketplace (PlayStation Store), a premium subscription service for enhanced gaming and social features (PlayStation Plus), movie streaming, rentals and purchases (PlayStation Video), a cloud-based television programming service (PlayStation Vue), music streaming (PlayStation Music, powered by Spotify) and a cloud gaming service (PlayStation Now).

Relation to the Metal Gear series
Aside from various Metal Gear games being downloadable via the PlayStation Store, and being equipped with the PlayStation Plus, several DLC was also issued via the PlayStation Store, and in the case of Metal Gear Solid: Peace Walker, also required getting specific passcodes via various related products.