Yes.
It runs a limited version of iOS 6 excluding several features only because the update would slow the phone down to the point of no usability with all of it.
There is no iPhone 3. You may be referring to the iPhone 3G or 3GS, which are the 2nd and 3rd generation iPhones respectively. Out of these two, only the 3GS can run iOS 6, while the 3G is stuck on iOS 4.2.1
Considering updating your iPhone forces you to update to the latest software available for the device, updating an iPhone 3GS now will update it to iOS 6.
The iPhone 5 will run iOS 6 or iOS 7.
iOS 6 is the software that was launched with the iPhone 5. You can run this software version on an iPod Touch (4th or 5th gen), any iPad except the original, and the iPhone 3GS, 4, 4S, and 5. You have only this summer to update to it if your device is eligible for an update to iOS 7 coming this fall. If you are running iOS 5, you can update to it from Settings>General>Software Update. If you are running any older iOS, you must plug your device into an iTunes-authorized computer to update. The update is entirely free by the way. You can see more about what features it brings on Apple's website.
At the moment iphone 6 runs ios 8.1.3
iOS 6 came out of beta September 21, 2012 with the launch of the iPhone 5. You can update to the latest iOS 6.1.3 (6.1.4 with the iPhone 5) by going into Settings>General>Software Update or plugging your device into an iTunes authorized computer if you are running anything older than iOS 5. If you are not fond of the iOS 7 update, then you must update to iOS 6 before this fall because after that, Apple forces you to only update to the latest software version or not at all. But you don't have to worry about this is you have a 4th gen iPod Touch or iPhone 3GS which can't get iOS 7.
Probably not. The only OS for iPhone currently in beta is iOS 6. There are is no iOS 5.1.2 currently in beta and iOS 6 should be out within a few weeks. Unless a security hole in the current iPhone OS is found before 6 is released, don't expect an update to iOS 5.
There is no iPhone 6. The iOS can be downloaded to earlier handsets, yes.
iOS 4.3 is a level iOS, Apple's mobile operating system, hence the name. Apple's iPhone, iPad and iPod Touch run iOS software. The latest level of iOS is iOS 5.1.1. However, it is expected that iOS 6 will be released at the WWDC this month. If you have any further questions regarding Apple and iOS, please contact me. Henryhen.
How to lock the orientation on the iPhone 3GS with iOS 4We show you how to lock the orientation on your iPhone 3GS running iOS 4 to prevent accidental rotationsEnabling rotation lock on the iPhone 3GSPublished on Jul 6, 2010The iPhone 3GS running iOS 4 can automatically switch between portrait and landscape orientations in many areas of the iOS interface.This can be tremendously useful. For example, many people find that viewing Web pages is better in portrait mode, but typing a URL into the address bar is much easier in landscape mode.There are many cases, however, when you'd rather have your iPhone stay in portrait mode even when it is tilted to the side. In these instances, you can easily lock your iPhone's orientation so it will no longer rotate.Follow these simple steps to lock the orientation of your iPhone 3GS:From any screen, double-tap the home buttonScroll as far left as you can on the multitasking dockThe first symbol to the left will be a circular arrowSelect this to either lock or unlock the orientation of your iPhone 3GSThat's it!
No, itunes supports it.
P0sixninja sells iPhone 5 and iOS 6 jailbreak exploits to an Apple employee