The Nexus S was the second "Nexus" device to come out of Google — after the Nexus One — in partnership with an Android manufacturer, in this case Samsung. Released in December 2010, the Nexus S was clearly cut from the same cloth as the original Samsung Galaxy S, though like the Nexus One it had specific Google flair. The Nexus S brought considerable spec improvements, including 16GB of internal storage, a 4-inch 480 x 800 display, 5MP camera, a 1GHz Hummingbird processor and 512MB of RAM. All packed in a curvy black body that was well received from a design standpoint.
The Nexus S was used as the launch device for Android 2.3 Gingerbread, bringing a redesigned interface with a new green and black color scheme, new keyboard, system-wide copy & paste refinements, as well as performance improvements. It also introduced native support for SIP/VOIP calls and NFC.
When Android 4.0 Ice Cream Sandwich was announced, the Nexus S was somewhat-surprisingly included in the update roadmap, even though the difference between Android 2.3 and 4.0 was quite dramatic. Further, the Nexus S even received an update to the first iteration of Jelly Bean, Android 4.1
The Nexus S came in two U.S. variants, one for AT&T (i9020A) and one for T-Mobile (i9020T), each being identical aside from radio bands supported for those two networks. There was also an i9023 model for global markets, and the m200 for Korea. In early 2012, the Nexus S was released on Sprint as the Nexus S 4G (SPH-D720), on account of its WiMax radio that offered higher data speeds. The GSM models supported up to HSPA+ 21 data speeds.
Though there have been many Nexus devices since the launch of the Nexus S, it will most definitely go down in history as an important building block of the Android platform and Nexus program as a whole.