Apple (AAPL) debuted its iPhone 15 and iPhone 15 Pro on Tuesday, bringing major changes to the company's most important devices including USB-C charging ports and a higher starting price for the iPhone 15 Pro Max.

Pre-orders begin Friday, September 15, with availability beginning Friday, September 22. The iPhone 15 and iPhone 15 Plus start at $799 and $899, respectively, while iPhone 15 Pro and iPhone 15 Pro Max start at $999 and $1,199.

The most notable change to both phone lines is their new USB-C charging ports. Rather than using Apple's proprietary Lightning port, all four phones come equipped with the universal standard. Apple made the switch to comply with a new European Union regulation that calls on electronics manufacturers to use USB-C in an effort to cut down on e-waste and make things easier for consumers.

USB-C is used by manufacturers across the spectrum of gadgets. The standard not only allows for fast data transfer speeds, but streaming video and universal charging, as well. In other words, you can use your USB-C laptop charger to charge your iPhone or your Nintendo Switch charger to charge your e-reader.

Still, longtime iPhone users will have to deal with the temporary annoyance of having to purchase new charging cables to replace any secondary ones they use throughout their homes or offices.

Outside of the iPhones, Apple is also bringing USB-C to the second generation AirPods Pro, as well as the ability to charge your AirPods from your iPhone.

IPhone 15 Pro and iPhone 15 Pro Max

Outside of USB-C ports, the new iPhones offer a host of additional upgrades. As usual, the iPhone 15 Pro and larger iPhone 15 Pro Max get the biggest updates, while the iPhone 15 and iPhone 15 Plus get a number of features from last year's iPhone 14 Pro line.

Both the iPhone Pro 15 and iPhone 15 Pro Max are built using titanium bodies, which Apple says makes them the lightest Pro models ever. The iPhone 15 Pro and iPhone 15 Pro Max sport new slimmer bezels that cut down on the phones' bodies, without reducing screen real estate.

Apple is also replacing the old mute button on the left side of the iPhone 15 Pro and Pro Max. The new, customizable action button lets you do everything from running custom shortcuts to firing up apps and powering up accessibility options. You can still use the button to mute your phone, but if you'd rather use it for something else, you can go ahead and do just that.

The iPhone 15 Pro and iPhone 15 Pro Max also include new camera systems with a 48-megapixel main sensor. While the iPhone 15 Pro still uses a 3x optical zoom, the iPhone 15 Pro Max gets a 5x optical zoom complete with a 25% larger sensor. That means you'll be able to capture crisper, more colorful subjects at further distances without any software degrading the image quality.

Users can also set new default zoom settings anywhere from the 0.5x ultra-wide zoom up to 3x zoom on the iPhone 15 Pro and 5x zoom on the iPhone 15 Pro Max. Apple has also included the ability to capture spatial videos that you can view on the company's Vision Pro headset.

Both the iPhone 15 Pro and iPhone 15 Pro Max also get Apple's new 3-nanometer A17 Pro chips. The chip, which Apple says is the fastest in any smartphone, features 19 billion transistors and features 6 CPU cores broken down into two performance cores and four efficiency cores. There's a 16-core neural engine that Apple says is 2x faster than before.

[Read more: Apple introduces the Apple Watch Series 9, starting at $249]

A new on-chip GPU features six cores and is 20% faster for peak performance. Improved efficiency, mesh shading, and ray tracing technologies should improve the overall gaming performance on the iPhone 15 Pro line. In fact, Apple went out of its way to highlight how much better games will run on the iPhone 15 Pro and iPhone 15 Pro Max. Gaming is an important category for Apple, as it helps power a large amount of App Store revenue. On that note, Apple said it is rolling out Capcom's "Resident Evil 8" and "Resident Evil 4" on the iPhone.

IPhone 15 and iPhone 15 Plus

Apple's iPhone 15 and iPhone 15 Plus are also getting improvements to a number of their systems. The displays now sport the company's Dynamic Island, the pill-shaped area at the top of the screen that houses their FaceTime and FaceID components. Dynamic Island provides users with an extra on-screen space for information including alerts such as phone calls, timers, Uber drop-off times, driving directions, music playback, sports scores, and more.

Apple says the the iPhone 15 and iPhone 15 Plus can reach peak brightness of 2,000 nits, allowing for improved high-dynamic range images and a better viewing experience in bright sunlight. Around back, the iPhone 15 and 15 Plus get slight curves to their rear panels making them more comfortable to hold when not wrapped in a case.

The phones come equipped with Apple's A16 Bionic chip from the iPhone 15 Pro line. That should give you a decent boost if you're using an older version of Apple's iPhone. What's more, Apple has built the iPhone 15 and iPhone 15 Plus with upgraded ultra-wide band chips that will help you find your friends with other iPhones in large crowds.

The iPhone 15 and 15 Plus get upgraded cameras with a 48-megapixel main lens with a quad-pixel sensor. Apple says this allows the iPhone and iPhone 15 Plus to group pixels to capture 24-megapixel images with better overall resolution.

There's also a 2x zoom option that simulates a telephoto lens by focusing in on the middle 12-megapixels of the main camera's sensor. The idea is to let you zoom in without distorting the overall image and without the need for a third camera lens. The iPhone 15 and iPhone 15 Plus both come with the ultra-wide lenses to capture wide-angle images.

Portrait mode is getting an upgrade with automated portraits, which, thankfully, works with dogs and cats. This will also allow you to adjust depth and focus in your photos after you capture them via the edit mode.

On the environmental front, Apple says the iPhone 15 and iPhone 15 Plus are built using 75% recycled aluminum, while their batteries use 100% recycled cobalt.

IOS 17

Both the iPhone 15 and iPhone 15 Pro lines come with the company's iOS 17. The software, which is available for every iPhone from the iPhone X and later, includes a variety of new features including updates to the Phone, Messages, and FaceTime apps, as well as a completely new StandBy mode that turns your iPhone into a kind of smart display when it's charging and on its side.

Changes to Phone, Messages, and FaceTime include new customizable, full-screen Contact Posters that show up on your friends' phones when you call them, Live Voicemail that transcribes messages as a caller is leaving them so you can answer them if the call is important, and FaceTime messages that let you send video messages.

StandBy mode turns your iPhone into a smart display when it's charging, allowing you to browse widgets, see the time, and get your notifications. A new Mental Health app, meanwhile, allows you to track your overall emotional wellbeing and help you determine your risk of anxiety and depression.

Correction: An earlier version of this article stated that pre-orders begin today. The article has been updated to note that pre-orders begin Friday, September 15, with availability beginning Friday, September 22.

Daniel Howley is the tech editor at Yahoo Finance. He's been covering the tech industry since 2011. You can follow him on Twitter @DanielHowley.

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