Glossary

Acronyms and terms used in this book.

A

ABI — Application Binary Interface. The contract between compiled binaries. Swift is ABI-stable as of Swift 5 on Apple platforms.

ADR — Architecture Decision Record. A short document capturing why an architectural choice was made.

APNs — Apple Push Notification service. Apple’s push notification delivery system.

ARC — Automatic Reference Counting. Swift/ObjC memory management; the compiler inserts retain/release.

ARKit — Apple’s augmented reality framework.

ATS — App Transport Security. iOS default that enforces HTTPS.

AsyncSequence — Swift’s protocol for asynchronous iterators (for await x in seq).

B

Background Task — Work scheduled to run when the app is not in the foreground (BGTaskScheduler, URLSession background uploads).

Binding — @Binding in SwiftUI; a two-way reference to state owned elsewhere.

C

Catalyst (Mac Catalyst) — Apple’s technology to run iPad apps on Mac with windowed chrome.

CKShare — A CloudKit record representing a sharing relationship between iCloud users.

CloudKit — Apple’s cloud storage backed by iCloud. Private and public databases.

Combine — Apple’s reactive streams framework (publishers, subscribers, operators).

CommandMenu — SwiftUI’s mechanism for adding entries to the macOS menu bar.

CoreData — Apple’s older object graph and persistence framework.

CoreML — Apple’s on-device machine learning framework.

CryptoKit — Apple’s modern cryptography API (AES.GCM, Curve25519, etc.).

D

Dependency Injection (DI) — Pattern of supplying dependencies to a type via initializer parameters instead of constructing them internally.

DispatchQueue — GCD’s serial/concurrent execution context.

dSYM — Debug Symbol file; lets Apple symbolicate crash reports.

Dynamic Island — Status / activity area on iPhone Pro models since iPhone 14 Pro.

E

Entitlement — A capability granted to an app via a .entitlements file and provisioning profile.

Existential — A type-erased value of some protocol; any P in modern Swift.

F

FairPlay — Apple’s DRM for video; also covers some App Store DRM.

FoundationModels — Apple’s framework for on-device LLM (Apple Intelligence).

G

GCD — Grand Central Dispatch. Apple’s queue-based concurrency primitive (older but still common).

H

HIG — Human Interface Guidelines. Apple’s design rules per platform.

HealthKit — Apple’s health/fitness data framework.

I

IAP — In-App Purchase. Purchases through Apple’s payment system (required for digital goods).

Instruments — Apple’s profiler (Time Profiler, Allocations, Leaks, Network).

IDFA — Identifier for Advertisers. Gated behind ATT (App Tracking Transparency) since iOS 14.5.

K

Keychain — Apple’s encrypted secret storage (passwords, tokens, keys).

L

Live Activity — A persistent UI on lock screen + Dynamic Island. ActivityKit framework.

M

MainActor — Global actor pinned to the main thread. @MainActor annotation.

MVC — Model-View-Controller. Classic UIKit pattern.

MVVM — Model-View-ViewModel. View binds to ViewModel state.

MV (in SwiftUI) — Model-View. The pattern where SwiftUI’s reactivity makes a ViewModel layer often unnecessary.

Module — A SwiftPM package or Xcode framework that publishes types and imports as a unit.

N

Notarization — Apple’s automated security check for Mac apps distributed outside the App Store; also required for App Store Mac apps.

NavigationStack — Modern SwiftUI navigation API (iOS 16+) replacing NavigationView.

O

Observable — Swift 5.9 macro @Observable marking a class as observable by SwiftUI.

OWASP — Open Worldwide Application Security Project. Authors of the Mobile Top 10 risk list.

P

PassKit — Apple Pay + Wallet pass framework.

Phased Release — App Store feature gradually rolling new versions to a percentage of users over 7 days.

Provisioning Profile — A file tying a developer’s certificate, entitlements, and devices/distribution rules; embedded in signed builds.

Q

QuickLook — Apple’s preview framework for documents, images, etc.

R

RealityKit — Apple’s AR rendering framework, ECS-based.

Result Builder — @resultBuilder attribute; foundation for SwiftUI’s ViewBuilder.

RxSwift — Third-party reactive framework (predecessor to Combine for many).

S

Sandbox — iOS / macOS isolation that restricts what an app can access.

Sendable — Protocol marking a type as safe to share across concurrency domains.

SceneKit — Apple’s older 3D rendering framework (largely superseded by RealityKit).

Secure Enclave — Apple’s hardware-isolated chip for cryptographic key storage.

Sign in with Apple — Apple’s privacy-focused federated identity. Required if you offer third-party social login.

SiriKit — Older framework for Siri integration (largely superseded by AppIntents).

SkyWatch / FitTrack / ShopKit / NoteSync / DevPortfolio / PlanBoard — The six capstone projects in Phase 13.

SPM — Swift Package Manager.

StoreKit 2 — Modern Swift-first API for In-App Purchases and subscriptions.

SwiftData — Apple’s Swift-native persistence framework (iOS 17+); built on Core Data.

Swift Testing — The new testing framework introduced in the Swift 6 era (@Test, #expect).

SwiftUI — Apple’s declarative UI framework.

T

TCA (The Composable Architecture) — Point-Free’s redux-style Swift framework.

TestFlight — Apple’s beta distribution platform.

TLS — Transport Layer Security. The protocol underlying HTTPS.

Transferable — Swift protocol for drag-and-drop / share content.

U

UIKit — Apple’s older imperative UI framework for iOS.

Universal Binary — A single Mac binary containing both Apple Silicon (arm64) and Intel (x86_64) code; metaphorically also used for iOS + iPadOS + Mac apps from one codebase.

Universal Link — A URL that opens the app if installed, or a web fallback if not. Configured via apple-app-site-association.

V

Vision — Apple’s framework for computer vision (text recognition, face detection, etc.).

VoiceOver — Apple’s screen reader.

visionOS — Apple Vision Pro’s OS.

W

WatchConnectivity — Framework for iPhone ↔ Apple Watch communication.

WidgetKit — Apple’s framework for home screen + lock screen widgets.

WKWebView — Modern WebKit-based web view (replaces UIWebView).

X

Xcconfig — Build configuration file (key-value, .xcconfig extension).

Xcode — Apple’s IDE.

XCTest — Apple’s older testing framework (still widely used).

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