Apple's annual September product event is happening Tuesday, and all signs point to it being huge. First, it'll be the inaugural event for the Steve Jobs Theater on the new Apple campus. Second, the company is expected to release three new iPhones, which is a change from recent norms. Third and most importantly, the iPhone 8 will be the showstopper of the event. It's expected to look very different from any iPhones that came before it, it'll sport a bunch of new features never seen before on an Apple handset, and it'll probably be expensive, too.

New iPhones aren't the only announcements to come on Tuesday: we'll likely see a new Apple TV and an updated Apple Watch. After the announcements made at Apple's WorldWide Developers Conference in June, we will also hear about forthcoming software releases. But make no mistake: this is primarily an iPhone event, and it might be the biggest one since the device debuted in 2007.

An iPhone by any other name...

We're assuming the next big iPhone will be called the iPhone 8, following Apple's numerical naming system, but we don't know for certain. Rumors suggest we'll see three new handset models on Tuesday: two with smaller updates that look familiar, and one totally new device. In that case, the most obvious naming system would be the iPhone 7S, the iPhone 7S Plus, and the wild-card iPhone 8.

But some reports suggest Apple may skip over the iPhone 7 "S" series altogether and name the new devices the iPhone 8, 8 Plus, and iPhone Edition. We've also seen mentions of names including the iPhone 10 (for the 10th anniversary of the original iPhone), the iPhone X, or the iPhone Pro.

No matter what it's called, what many have dubbed the iPhone 8 will be the device with the most changes. The other two models may follow previous "S" generations, which means they'll receive incremental updates, including better cameras and a processor upgrade.

Apple will make a statement with the iPhone 8 in design and features. Reports suggest the iPhone 8 model will be similar in size to the 4.7-inch iPhone but have more screen space than ever thanks to an edge-to-edge display design. This model is expected to have Apple's first OLED display on an iPhone as well, which means the device would consume less power while offering better contrast and color payoff. An OLED panel would also allow Apple to produce a thinner device overall, which is something all smartphone OEMs love to do whenever possible.

But OLED displays come with compromises: they don't have as long of a shelf life as their LCD counterparts, and they can be more prone to burn-in, which is when the ghost of an image sticks to the screen for a bit. Apple is likely hoping the benefits of OLED will outweigh the compromises, especially if the panel's energy efficiency allows for a longer battery life.

The purported edge-to-edge display affects a lot on the front of the iPhone. To accomodate this design, Apple has to shave off as much of the top, bottom, and side bezels as possible, in addition to removing the physical Home button and possibly altering the position of the front-facing camera, speaker, and mic. One report says that the iPhone 8 will forgo the physical Home button entirely, while the fate of Touch ID is less clear.

Other reports say Apple will do away with Touch ID entirely by using new 3D-imaging software in the front-facing camera to create a facial recognition unlocking system. Instead of using your fingerprint to unlock the iPhone 8, you'd only need to place your face in view of the front-facing camera. Still other reports suggest the new facial recognition software will just be an alternative to Touch ID and that the technology will be built "underneath" the OLED display.

Evidence of a facial recognition system was recently uncovered in Apple's HomePod firmware. Numerous "FaceDetect" methods were found buried in the new home speaker's firmware, suggesting the new system can identify faces from multiple angles and from various distances. References were also made to infrared technology, so we may see the inclusion of an infrared camera on the front of the iPhone 8. This system is rumored to be even more secure than Touch ID since it captures more data points about your face than Touch ID does about your fingerprint. In addition to unlocking the new iPhone, the facial recognition system could be used with Apple Pay to authorize payments.

Apple did confirm that a facial recognition system is in the works, but we won't know in what capacity it'll be implemented in the iPhone 8 until the launch. While the HomePod firmware gave us some insight into the facial recognition feature, it did not provide insight into the fate of Touch ID. There were no mentions of an under-the-screen Touch ID system, and some reports suggest production problems may have stalled that feature. Either way, Touch ID isn't totally dead—if the other two new iPhones follow the "S" protocol, they will likely still have a physical Home button that supports Touch ID.

Talk has been circulating about the rear cameras on the iPhone 8 as well. The handset could have a vertical dual-lens camera on the back, which would be different from the horizontal setup found on the iPhone 7 Plus. There could be optical image stabilization on both cameras, which would be another departure from the 7 Plus that has OIS only on its wide-angle lens. The new camera combo may have an integrated 3D system for capturing objects in 3D in photos and could also be used in augmented reality programs.

Apple may be ditching aluminum for the new smartphone's body and going back to glass. Every iPhone from the iPhone 5 until the most recent iPhone 7 models have aluminum bodies, but Apple may go back to a glass design similar to that of the iPhone 4. Some reports suggest the glass body will be built around a stainless steel frame, similar to how the Apple Watch is constructed. Despite the change, the iPhone 8 is still expected to be water-resistant, like the iPhone 7.

The body of the handset will also serve another purpose: wireless charging. Apple is expected to include induction-based wireless charging technology in the iPhone 8 and sell a separate accessory that would allow the device to be charged without being plugged in. The accessory may be similar to the Apple Watch's charger, as that device can only be charged wirelessly using induction-based technology. The iPhone 8 will likely still have Apple's Lightning connector that supports charging, but the wireless option will be available to those willing to spend the extra money on the optional accessory.

Another factor that could improve battery life is a new processor. We'll likely see a new chip in each new handset, possibly the A11, which reports say Apple has been testing with a 10-nanometer production process. Reducing the size of the processor from 16 nanometers to 10 can make the devices more efficient even with all the new features included.

As far as pricing goes, most reports speculate the iPhone 8 will start at $999. This would make it the most expensive base iPhone model ever. Not much has been said about storage and RAM options: any new iPhone models will likely have either 2GB or 3GB of RAM, and the base models will likely have 64GB of storage. If that's true, we could see iPhone 8 pricing as such: $999 for the 64GB model, $1,099 for the 256GB model, and $1,199 for the 512GB model.