1. iOS：
iOS是苹果公司提供的移动操作系统。它主要是为iPhone和iPod Touch等Apple移动设备设计的。它以前被称为iPhone OS。它是基于Darwin(BSD)操作系统的类Unix操作系统。它是仅次于Android的世界第二使用最多的移动操作系统。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年发布。
2. NetBSD：
NetBSD是由NetBSD Foundation提供的免费开放源代码操作系统。它基于Berkeley软件发行版。它是一个类似Unix的操作系统。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项目着重于精心设计，在许多计算机体系结构中的代码清晰度和可移植性。 NetBSD的源代码是公开可用的，并已获得许可。 NetBSD的第一个版本于1993年发布，其内核类型是单片的。
iOS和NetBSD之间的区别：
| 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. |