In Plane Switching(IPS) technology was first introduced by Hitachi in 1996 to improve the quality of the displays on the LCDs.
It basically deals with colour schemes and viewing angle problems in LCDs.
This technology like any other technology was first very expensive and due to the high cost involved it was used by very few people, most of them being graphic professionals.
Now in the 21st century this technology has become much more cheaper and thus can be used commonly in daily use devices.
Steve Jobs(C.E.O Apple) first introduced this technology in the revolutionary and magical Apple product- The Apple iPad which has by far been the best tablet ever sold on this earth. It used the multi touch IPS technology. From the Apple iPad point of view this technology was very important keeping in the mind that the iPad has to be tilted while gaming and media viewing. Apple has been very sensible here by using the IPS technology
Later the IPS technology was introduced in the Apple iPhone 4 which too required this technology during gaming and media viewing.IPS technology along with the Retina Display makes the overall display a real sensation, by far it is the best display that a mobile phone can have.
Finally the latest release by Apple was the new Apple iMacs where it has used the IPS technology with crystal liquids to enhance the display. With the HD becoming common Apple has to be one step ahead of the others and by introducing the IPS technology in the new Apple iMacs Apple is doing just that.