Apple has a suite of features known as Continuity that allow your iPhone and Mac to work together as if they were a single device.

Introduced in macOS Sequoia and enhanced in macOS Tahoe, this is the flagship “together” feature.
iPhone Mirroring can be used with only one Mac and one iPhone at a time.
Important: To use iPhone Mirroring, it must be available in your country or region. iPhone Mirroring is currently unavailable in the European Union.
Apple Documentation: https://support.apple.com/en-us/120421

Your iPhone has a much better lens than your MacBook’s built-in webcam. This feature lets your Mac “borrow” the iPhone’s eyes.
Apple Documentation: https://support.apple.com/en-us/102546

Copy & Paste: Copy text, an image, a video, or a link on your iPhone, and simply press Cmd + V on your Mac or iPad to paste it there instantly. It works both ways and feels like they share a single memory.
To use Universal Clipboard to copy entire files from one Mac to another, each Mac requires macOS High Sierra 10.13 or later.
Apple Documentation: https://support.apple.com/en-us/102430

Allows you to start a task on one device and finish it on another.
Seamless Transition: If you start writing an email or browsing a website in Safari on your iPhone, an icon appears in your Mac’s Dock. Clicking it opens that exact page or draft on your computer.
Handing off a FaceTime call requires iOS 16 or later, or iPadOS 16 or later.
Handing off a FaceTime call requires macOS Ventura 13 or later.
Apple Documentation: https://support.apple.com/en-us/102426

If you are traveling and have no Wi-Fi, your Mac can remotely wake up your iPhone’s Personal Hotspot.
No Password Needed: You don’t even have to touch your phone; you just select your iPhone from the Wi-Fi menu on your Mac. It even shows your phone’s battery life and signal strength in the Mac’s menu bar.
The iPhone or iPad must have an activated carrier plan providing Personal Hotspot service.
Apple Documentation: https://support.apple.com/en-us/109321