Firstly, because the iPhone makes up around half of the company's total revenue every year so it's a pretty big deal for the $3 trillion company. Secondly, there's just so many people with iPhones and many of them are either keen to get the shiny new thing, or are long overdue for an update.
Announced this morning at Apple's Cupertino headquarters inside the Steve Jobs Theatre, the iPhone 15 is the latest culmination of all that Apple has learned about smartphones and the technologies they have created since that first iPhone way back in 2007.
iPhone 15 USB-C: Farewell Lightning, hello new charging port
After a ruling by the European Union Apple has been forced to change its successful and proprietary Lightning charging connector to the universally used USB-C port for this new iPhone 15 range.
This means that if you purchase a set of headphones, or a bluetooth speaker, the cable that comes with it will also work to charge your iPhone.
Apple did not acknowledge the EU ruling, instead referring to the change by saying "USB-C has become a universally accepted standard".
Hours away from the new iPhone, here's where it all began
The company went on to say the iPhone 15 "uses powerful wired and wireless technologies" and pushing its wide range of MagSafe wireless charging and connectivity options.
While USB-C is across the entire iPhone 15 range, iPhone 15 Pro models have the capability to support faster data transfer speeds using USB-C on a compatible USB 3.0 cable.
iPhone 15 colours and design
As is always the case, the basic iPhone model will come in a range of colours. Apple this year turns to a more pastel colour palette, with pink, yellow, green and blue all featuring alongside a black iPhone 15.
It's the first time Apple has had an explicitly pink phone in its flagship range; the closest before this was the pink iPhone 5C and rose gold coloured iPhone 7.
The Pro model iPhone 15, as always, is a bit more subdued with a black (midnight) and cream (starlight) options and a new blue.
In a major change to the construction of iPhone, the Pro models of the iPhone 15 will feature a titanium outer construction, a different look to stainless steel but importantly also much lighter, making the overall weight reduction a blessing for users of the largest iPhone 15 Pro Max models.
Apple describe it as the "most premium material ever used in an iPhone" while also being more durable, becoming the lightest iPhone Pro model ever.
The screen edges are reduced, making the display sizes of 6.1 inches and 6.7 inches push further to the edge of the physical device than ever.
From a software perspective, the iPhone 15 and 15 Plus get the Dynamic Island that debuted on the iPhone 14 Pro models last year.
This upper area of the screen brings the camera and sensors to within the screen, and that area becomes usable by software makers to display contextual information at a glance.
iPhone 15 Pro action button
The mute switch on the side of the iPhone has been there since its launch in 2017. The iPhone 15 Pro models farewell the switch, replacing it with a programmable action button.
Users of the Pro models can customise the Action button to do whatever they can imagine.
Examples used by Apple include a simple press to mute or unmute, launching the camera or another app, starting a voice memo or putting your phone in Do Not Disturb mode.
The regular iPhone 15 and 15 Plus still have the mute switch as per previous phones.
iPhone 15 camera advancements
Entry-level iPhone 15 models will now feature camera technology previously seen on the iPhone 14 Pro range. This includes a 48-megapixel main camera, which allows for greater detail capture.
Pixels are combined together to increase light capture, which improves the overall image quality, while focus is improved with every single pixel acting as a focus pixel for your images.
Again, computational photography allows the device itself to improve not just the light and detail, but combines all the data captured to allow for the best quality and resolution from an iPhone that's not a pro model.
Portrait photography has been given a detailed overhaul in what Apple is calling "Next Generation Portraits", again improving what we're able to do with an entry level iPhone.
On the iPhone 15 Pro, the 48-megapixel sensor is improved with the addition of new preset focal lengths for photographers on the main lens.
On the Pro Max, there will be a new 5x zoom with 120-millimetre focal length and an f2.8 aperture.
Light is reflected four times within the lens to give this advanced zoom without a huge additional size to the lens. This same lens also features improved image stabilisation.
Night mode and other low light photography is improved on all three lenses on the iPhone 15 Pro models.
Both iPhone 15 Pro models will also support the capture of "Spacial Videos", which are essentially a 3D video format that will be supported on the new Apple Vision Pro headset launching next year.
iPhone 15 Pro Max, Pro and other models
As with recent years, there will be four iPhone 15 models, the iPhone 15, iPhone 15 Plus, both of which have the same powerful processor (A16 bionic) as last year's iPhone 14 Pro models, while the iPhone 15 Pro and iPhone 15 Pro Max feature a new A17 Pro Chip.
iPhone 15 Pro models feature the triple lens camera system, while the 15 and 15 Plus feature a dual lens camera.
iPhone 15 price in Australia
Pre-Orders for the iPhone 15 series start this Friday, September 15, at Apple, major retailers and all the major telcos.
The iPhone 15 starts at $1499, with $1,649 for the Plus.
The iPhone 15 Pro starts at $1849 and the iPhone 15 Pro Max starts at $2199
Trevor Long Travelled to Cupertino as a guest of Apple Australia
