You'll need to sign up to use Apple Intelligence when iOS 18 launches this fall, but there'll be a waitlist and performance issues during a limited beta preview.
Apple Intelligence will have a waitlist at first
macOS Sequoia
macOS Sequoia system requirements: Is your Mac compatible with macOS 15?
If your Mac laptop or desktop meets the system requirements for macOS Sonoma, it's also compatible with Sequoia— with the exception of certain MacBook Airs.
Continuity and Screen Sharing to play major roles in macOS Sequoia, iPadOS 18, & iOS 18 updates
In a major change that’s sure to get people fired up, Apple is enhancing Continuity and Screen Sharing features between Apple devices, to include Macs, iPhones, and iPads starting with macOS Sequoia when paired with iOS & iPadOS 18.
iOS 18 developer beta available today, with public betas arriving in July
Those who aren't registered developers can test-drive iOS 18 and the new Apple Intelligence features when a public iPhone beta drops in July.
How to install macOS Sequoia on a different partition of Mac
Learn how to install macOS Sequoia on a different volume (disk partition) and have two macOS versions simultaneously on your Mac.
How to create a bootable USB installer for macOS Sequoia
Learn how to get macOS Sequoia on a USB thumb drive and use it to install macOS 15 on multiple Macs without needing to download the large macOS file each time.