Android
The Google service that distributes apps to Android devices and enforces app policies.
Google Play Store.
This iOS security chip isolates Touch ID/Face ID data and handles secure boot and encrypted storage keys.
Secure Enclave.
The kernel subsystem that manages hardware interrupts and assigns them to CPU cores.
The IRQ subsystem.
Windows subsystem that stores configuration data in a hierarchical database.
Windows Registry.
macOS uses this filesystem designed by Apple with features like snapshots and strong encryption
APFS (Apple File System).
A tool that developers use to connect a phone to a computer for debugging, file transfer, and installing apps from the command line.
ADB (Android Debug Bridge).
This iOS architecture allows apps to run tasks in the background only under strict modes like audio playback, VoIP, or navigation.
Background execution modes.
This Linux feature creates isolated environments with their own processes, networking, and filesystems without using full virtualization.
Linux namespaces + cgroups (containers).
This Windows feature allows running Linux binaries natively without a traditional virtual machine.
WSL (Windows Subsystem for Linux).
This subsystem manages applications, memory compression, and unified memory on Apple Silicon Macs.
XNU kernel (Mach + BSD components).
What is Android?
This Google-owned mobile OS is based on the Linux kernel and is widely used on smartphones.
The framework that manages UI rendering on iOS, built on top of Core Animation and optimized for 120Hz devices.
UIKit (working through Core Animation).
The Linux file permission model includes three entities. Name them.
Owner, group, others.
The Windows process that acts as the "session manager" during early boot and launches subsystem processes.
smss.exe (Session Manager Subsystem).
macOS apps must declare capabilities in a specific file to access hardware like camera or microphone.
Info.plist entitlements / Privacy keys.
Android feature that allows apps to run in the background with restricted CPU use; important for battery life.
Doze mode / App Standby.
iOS uses this mechanism to isolate app processes and restrict access to system resources, enforcing per-app entitlements.
Mandatory Code Signing + Sandbox + Entitlements.
A high-performance I/O scheduling algorithm that is optimized for SSDs and low-latency systems.
The "none"/"noop" or "mq-deadline" scheduler.
The isolation technology that runs modern Windows apps (UWP/MSIX) in a lightweight sandbox.
AppContainer.
macOS uses this technology to protect system files by preventing modifications even by root.
SIP (System Integrity Protection).
The Android system uses this component to manage system resources and application process lifecycles; it is part of the architecture that runs apps (hint: it was replaced in newer versions by Android Runtime improvements).
Dalvik / ART (Android Runtime) — ART is the current runtime.
This advanced memory protection technique in iOS randomizes memory locations to prevent predictable exploitation.
ASLR (Address Space Layout Randomization).
The kernel memory allocator used for small, frequent allocations; Linux replaced SLAB with this more scalable allocator.
SLUB allocator.
The low-level kernel component responsible for scheduling threads and handling CPU affinity.
The Windows Kernel Scheduler.
The optimized JIT/AOT hybrid runtime used for Swift and Objective‑C apps.
Swift runtime + Objective‑C runtime (with dyld and LLVM optimizations).