Apple (AAPL -0.81%) hosted its 2018 iPhone event this morning, unveiling updates to its most important product line. As is often the case, just about everything was widely leaked or rumored heading into the event, although there was one notable curveball.

CEO Tim Cook also said the Mac maker is approaching a major milestone: Apple is about to ship its 2 billionth iOS device. It's been over two years since it shipped its billionth iPhone, but the new milestone includes all other iOS devices, like iPod Touch and iPads.

Here's everything Apple showed off today.

Woman using iPhone Xs Max in the rain

Image source: Apple.

Apple Watch Series 4

Starting with the Apple Watch -- which Apple boasts is now the No. 1 watch in the world, not just the No. 1 smartwatch -- the company unveiled the Apple Watch Series 4. The new version is thinner than previous generations and features a larger edge-to-edge display that can show more information. The Digital Crown is getting haptic feedback, and various other aspects of the wearable device, like the speakers and back, have been redesigned.

Two Apple Watch Series 4 models next to each other

Apple Watch Series 4. Image source: Apple.

There are the expected internal spec bumps, including a new System-in-Package (SiP) S4 that powers the Apple Watch, and a new accelerometer and gyroscope that allow the device to detect falls. The headline addition is the inclusion of electric heart rate sensors, which are capable of taking electrocardiograms (ECG or EKG), in line with prior rumors. Apple notes this is the first ECG product that average consumers can purchase over the counter, and it importantly has already obtained Food and Drug Administration (FDA) clearance. Commercial ECG machines cost thousands of dollars.

Battery life is unchanged at approximately 18 hours, and new versions still will work with all existing Apple Watch bands -- which is good news for band enthusiasts who may have amassed band collections over the years. Prices are going up, though, likely due to the extra costs related to developing the ECG system and related components. The Series 4 is starting at $399 for GPS models; adding a cellular connection (which is helping drive demand these days) bumps that up by another $100. Series 4 pre-orders start on Friday and ship on September 21.

Three new iPhone X variants

For the feature presentation, Apple showed off the trio of iPhone models that were widely expected. Reverting back to its "S" naming scheme, there's the iPhone Xs (pronounced "ten ess"), which is mostly a refresh of last year's iPhone X. The same 5.8-inch OLED display is back, but with greater dynamic range and faster touch-sensing.

There's a new iPhone Xs Max that includes a larger 6.5-inch OLED display, the largest the company has ever put into an iPhone. The Xs Max is about the same size as older Plus models but features a larger edge-to-edge display. Both the new Xs and Xs Max will get a third color option: gold. Of course, Face ID is included.

iPhone X lineup

iPhone Xs. Image source: Apple.

Other improvements include smart HDR, improved depth effects where users can adjust depth of field after the fact, slightly longer battery life, and faster LTE. Apple's chip prowess remains unparalleled, with new A12 Bionic powerhouses inside.

The A12 Bionic is the first 7-nanometer chip and includes a 6-core CPU alongside a 4-core GPU, all of which is custom designed by Apple. The company also is making significant strides with its Neural Engine, which is dedicated to machine learning and artificial intelligence. There's also support for dual SIMs (one physical SIM and one eSIM, except in China where Apple will sell versions that support two physical SIMs), which will make life easier for globetrotters.

The third model is the iPhone XR, which borrows from the same overall design as the iPhone X but uses aluminum instead of stainless steel for the chassis and a traditional LCD instead of OLED for the 6.1-inch display. XR will come in six different colors, offering more personalization. It uses the same edge-to-edge display design, which means Apple has gotten rid of the Home Button completely in the 2018 lineup, a natural step after doing likewise in iPhone X last year.

Blue iPhone XR

iPhone XR. Image source: Apple.

The aforementioned curveball is pricing. It was rumored that Apple would reduce pricing on the Xs, but Apple decided to stand pat. iPhone Xs starts at the same $999, while iPhone Xs Max will set you back $1,099. iPhone XR will be the most affordable of the bunch, starting at $749. The company also is going back to three storage tiers for all models.

iPhone Xs and Xs Max are available for pre-order on Friday and will ship on September 21. iPhone XR won't be available for pre-order until October 19 and will ship on October 26.

What we didn't hear about was a new iPad. Some were hoping that Apple would show off the rumored iPad Pro that has Face ID and an edge-to-edge display, but it seems that device isn't ready to ship quite yet.