The equals sign means is equal to. It is telling us that one thing equates to another; that they are the same.
The iPhone 4 is the most recent iPhone to be discontinued from the iOS Update cycle. It did not receive the iOS 8 update, so it's final software version is iOS 7.1.2. You can update to this version through iTunes, or download it from an IPSW repository like this website: https://ipsw.me/.
As of November 2012, the S III is part of a high-profile lawsuit between Samsung and Apple. In November 2012, research firm Strategy Analytics announced that the S III had overtaken Apple's iPhone 4S to become the world's best-selling smartphone model in Q3 2012.