1.iOS：
iOS 是由 Apple Incorporation 提供的移动操作系统。它主要是为 iPhone 和 iPod Touch 等苹果移动设备设计的。它早先被称为 iPhone 操作系统。它是一个基于Darwin(BSD) 操作系统的类Unix 操作系统。它是仅次于 Android 的全球第二大移动操作系统。它主要用 C、C++、Objective-C、汇编语言和 Swift 编写。 iOS 的第一个版本于 2007 年推出。
2.NetBSD：
NetBSD 是由 NetBSD 基金会提供的免费开源操作系统。它基于 Berkeley Software Distribution。它是一个类Unix操作系统。它可用于许多平台，包括服务器、台式机、手持设备和嵌入式系统。 NetBSD 项目侧重于跨许多计算机体系结构的精心设计、代码清晰度和可移植性。 NetBSD 的源代码是公开可用的，并获得许可。 NetBSD 的第一个版本于 1993 年推出，其内核类型是单片的。
iOS 和 NetBSD 的区别：
| S.No. | IOS | NETBSD |
|---|---|---|
| 1. | It was developed by Apple Incorporation. | It was developed by The NetBSD Foundation. |
| 2. | It was launched in 2007. | It was launched in 1993. |
| 3. | Its target system types are smartphone, music player and tablet computer. | Its target system types are NAS, server, workstation and embedded systems. |
| 4. | Computer architectures supported by iOS are ARMv8-A (iOS 7-present), ARMv7-A (iPhone OS 3-iOS 10) and ARMv6 (iPhone OS 1-iOS 4.2.1). | Computer architectures supported by NetBSD are IA-32, x86-64, ARM, MIPS, PowerPC and sparc64. |
| 5. | Its kernel type is Hybrid. | Its kernel type is Monolithic with modules. |
| 6. | Its native APIs are Cocoa and BSD-POSIX. | Its native APIs are BSD-POSIX. |
| 7. | It has preferred license is Proprietary, APSL and GNU GPL. | It has preferred license of BSD. |
| 8. | Its update management is Software Update. | Its update management is by source or network binary update. |
| 9. | The non-native APIs are not supported through its subsystems. | The non-native APIs supported through its subsystems are Linux and others. |
| 10. | File systems supported by iOS are HFS+ and APFS. | File systems supported by NetBSD are UFS, UFS2, ext2, FAT, ISO 9660, NFS and LFS. |