Apple is expected to introduce iPhone 15 models Tuesday during its annual keynote presentation aimed at giving people more reasons to buy its latest devices.

The showcase at Apple's Cupertino, California, headquarters comes as the company is mired in a mild slump that has seen its sales drop from last year in three consecutive quarters — with management signaling another downturn is likely during the current quarter even as the iPhone 15 is released.

The array of iPhone 15 choices are expected to consist of mostly incremental advances to the device's chips, battery and cameras; rather than major leaps in technology.

But if the rumor mill pans out, this year's iPhone 15 Pro and Pro Max may feature a telephoto lens that will improve the quality of photos taken from far distances.

One of the biggest changes that Apple is expected to announce is a new way to charge the iPhone 15 models and future generations. The company is expected to switch to the USB-C cable standard that is already widely used on many devices, including its Mac computers and many of its iPads.

Apple is being forced to start phasing out the Lightning port cables that it rolled out in 2012 with the release of the iPhone 5 because of a mandate that European regulators are imposing in 2024. It's unclear whether Apple will initially limit the switchover to USB-C ports to models made specifically for the European market or make the change worldwide.

Besides its new iPhones, Apple also typically uses this annual showcase to unveil its next generation of smartwatches — a product that made its debut nearly a decade ago.

The next version of the software that powers iPhone devices also is soon to be released. That operating system, iOS 17, will be available as a free download later this month and will include features such as the ability to read a transcription of a message with an option of deciding to talk to the person on the line before the voicemail is finished.

Copyright 2023 NEWSnet and The Associated Press. All rights reserved.