PlayStation Plus is the online service which gives free games and discounts and keeps on giving to the loyal Playstation fans. Once your subscription expires your downloaded delights are all taken away from you.
However, when you re-subscribe, you are given the digital rights back to all previous downloaded games and can begin enjoying them immediately. While PlayStation Plus is mandatory for online play on the PlayStation 4, the same great benefits apply. Also, PlayStation Plus will work on the PlayStation 4, PlayStation 3 and the PlayStation Vita under the same account, meaning that its a one time buy for your PlayStation