Apple iPhone 8 invite hidden secrets
Apple has invited analysts and the media to an event at its new headquarters on 12 September.Apple

Apple is holding a media event at the new Steve Jobs Theatre on 12 September. It is the first event to take place at the 1,000-seat auditorium, which sits in the grounds of Apple Park, the company's new $5bn (£3.9bn) California headquarters.

The event, which comes a year after Apple revealed the iPhone 7 and 7 Plus, kicks off at 10am local time (6pm BST). Members of the media received invitations to the event on 31 September.

These are the facts. But, this being an Apple event and almost certainly the launch of the most significant iPhone yet, there is still plenty to discuss as we count down the days to the 12th. Here is everything we expect to see.

Introduction and welcome

'Thanks for coming. We have lots to talk about today. Everything has sold really well'

Most Apple events start this way. Chief executive Tim Cook will walk onto the stage, say he and his team have an awful lot to discuss, then quickly fire through how obscenely well Apple is doing. Expect a short video with happy music of a new store being opened, or Apple products being used for a good cause.

Apple Park

Apple Park headquaters
The enormous new Apple Park campus cost $5bnGetty

This is the first event at Apple Park, and even though the UFO-like headquarters isn't quite finished, expect Cook to have plenty to say about how shiny, new and terribly well designed everything is. Responsibly sourced, self-sufficient and oh-so green. Then a video narrated by Apple design head Jony Ive.

Next up, software. We've already seen most of this before, so the biggest takeaways will be the release dates of iOS 11 for the iPhone and iPad range, watchOS 4 for the Apple Watch, tvOS 11 for the Apple TV and macOS High Sierra for the Macs.

iOS 11

Apple announces iOS 11
iOS 11 is a major new update for the iPhone and iPadApple

An all-new and customisable Control Centre, plus restyled notifications and lock screen take centre stage on iPhone. But the big news is iOS 11 on the iPad, which brings a Mac-style dock and greatly-improved multitasking capabilities. This is Apple's big play to turn the iPad into the laptop-killer it was always supposed to be.

watchOS 4

Again, we have seen most of this before. Siri comes to the Apple Watch, plus a range of new watch faces, new complications, faster third-party apps and more exercise features.

tvOS 11

As with previous Apple TV software updates, there won't be a great deal said here. Some user interface tweaks will play second fiddle to new 4K-ready hardware.

macOS High Sierra

An update to last year's macOS Sierra, the new operating system includes virtual reality support and a range of updates for Siri and the Safari web browser. Most of the changes are under the hood, resulting in improved performance over Sierra, but with few major visual changes.

Safari prevents auto-play videos from starting without your permission on websites you visit, and a new tracking feature prevents websites from gathering data about you to sell to advertisers. This doesn't block ads, but instead prevents companies from displaying adverts based specifically on your browsing habits.

Siri's voice has been made to sound more natural, with extra expression and changes in intonation based on what is being said. Notes, Spotlight and Facetime also receive minor updates.

Apple Watch Series 3

Apple Pay on Apple Watch
A third-generation Apple Watch is expected to include its own 4G connectionIBTimes UK

Now we're getting to the meat of the event; new hardware. But as Tim probably said earlier, there's a lot to cram into two hours so this will be a whistle-stop tour of the new Apple Watch, which is expected to have its own LTE connection. In English this means 4G and the ability to connect to the internet without first tethering to your iPhone over Bluetooth.

Will the new Watch require it's own phone number? Will it use the same as your iPhone? How will the networks make this happen? Will they charge extra for the privilege? So many questions and, for now, no answers.

Should a new model arrive, the year-old Series 2 and updated Series 1 will likely remain on sale at reduced prices.

Apple TV 4K

If it happens, this will be a simple one. The Apple TV set-top box will get an update to stream Ultra HD content, also known as 4K. This will mean access to Ultra HD content from services such as Netflix, and will pave the way for iTunes to finally hop aboard the super-sharp 4K bandwagon.

A 4K iTunes service on 12 September seems unlikely, as Apple is believed to still be haggling with Hollywood over prices. We suspect it might be next year before the films actually arrive, and no doubt it'll be US first and the UK later.

HomePod extra details and release date

Apple HomePod
The HomePod is a home speaker by Apple controlled by voice commands via SiriApple

Apple unveiled the HomePod at a media event earlier in the year and said it would go on sale by December. 12 September might still be a little early, but let's hope for an update nonetheless. With every tech company and their dog getting in on the smart speaker act, Apple can't be seen to lag behind for too much longer.

iMac Pro extra details and release date

It's a similar story with the iMac Pro, which was teased at Apple's last event, WWDC, in June. A pumped-up, Space Grey coloured desktop computer, the new Pro should go on sale before the year is out. Prices and a release date can't be far away.

iPhone 8 and 8 Plus

iPhone 8 dummies show new copper colour
Image clams to show a new copper colour option for the new iPhoneWeibo

A year on from the iPhone 7, we fully expect Apple to stick to tradition and announce two new models, called the 8 and 8 Plus. The rumour mills expect these handsets to trade in the aluminium backs of their predecessors for glass, thus making wireless charging possible for the first time on an iPhone.

We also expect to see the usual annual performance upgrades Apple is known for. A bit more RAM, a faster processor and perhaps increased storage options; maybe even a new colour. Prices will likely stay close to what Apple is currently charging for the iPhone 7 and 7 Plus.

iPhone X

Apple iPhone 8 AR render
Fan-made renders show how an iPhone Edition with Siri-powered augmented reality could lookGabor Balogh

And so, to the main event. Whether it is called the iPhone 8, the iPhone Pro, the iPhone Edition or, as we are no led to believe, the iPhone X, this is a big one for Apple. Ten years after Steve Jobs revealed the original, and with the competition from Samsung and Google fiercer than ever, Apple can't leave anything on the table.

Widespread rumours claim the new iPhone will have a design unlike any of its predecessors. It will be no larger than the iPhone 7, but with a screen longer than that of the iPhone7 Plus. Thiswill be achieved by employing a design which stretches the display to the phone's four edges.

It will have 3GB of RAM (50% more than the iPhone 8) and be unlocked by a new feature called FaceID. Replacing the fingerprint-based TouchID of previous iPhones, the new system takes a 3D scan of the owners face. The hardware can also be used to place the user's facial expressions onto a new suite of animated emoji.

The home button, we are told, will be removed and replaced by either an on-screen alternative, or a new swipe gesture. iOS will look different on the new iPhone, thanks to extra space at the top and bottom of the display, and there will likely be more storage and even faster performance. The iPhone Edition will need this to justify the rumoured £1,000-plus price tag.