Software refers to computer programs. Programs are the instructions that tell the computer how to process data into the form you want. There are two kinds of software: system software and application software.
软件指的是计算机程序。程序是告诉计算机如何将数据处理成你想要的形式的指令。有两种软件：系统软件和应用软件。
System software is a collection of programs that enables application software to run on a computer system's hardware devices, it is background software and includes programs that help the computer manage its own internal resources.
系统软件是指能让应用软件在计算机系统硬件设备上运行的程序的集合，它是后台软件并且包括帮助计算机管理自己内部资源的程序。
Application software is a specialized programs that enables the user to accomplish specific tasks.
应用软件是让用户能够完成特定任务的专门程序。
In this text, we mainly discuss system software.System software consists of four kinds of programs: bootstrap loader, diagnostic routines, basic input-output system, and operating system. Among these four parts, the operating system is we most concerned with, whith helps manage computer resources. Most important operating systems are: Windows, Windows NT, OS/2, Macintosh, and Unix.
在这一节中，我们主要讨论系统软件。系统软件由四种程序组成：引导装入程序、诊断例程、基本输入输出系统和操作系统。在这四种当中，操作系统是我们最为关心的，它帮助管理计算机资源。最重要的操作系统有Windows、Windows NT、OS/2、Macintosh和Unix。
Windows —Windows gets its name because of its ability to run multiple applications at the same time, each in its own window. Windows offers graphical user interface (GUI), presents the user with graphic images of computer functions and data. It provides a standard mechanism for copying or moving information from one program to another. This mechanism, called the Clipboard, means that information created in one context is instantly reusable in another, you don't need to reenter information or work with clumsy data-transfer utilities. Windows also has DDE (dynamic data exchange) and OLE (object linking and embedding) functions. In DDE two or more applications can be linked. This way, data created in one application is automatically entered into the others. OLE, like DDE, links data between applications. Additionally, OLE allows the application receiving the data to directly access the application that created the data.
Windows之所以称为窗口是因为它具有能同时运行多个应用程序的能力，并且每一个程序有其自己的窗口。Windows提供图形用户界面，给用户提供计算机的功能和数据的图像。它提供标准的机制用于将信息从一个程序拷贝或移动到另一个程序。这个机制被称为剪贴板，意味着在一个文本中产生的信息可以被另外一个文本立即重新使用，而用户不需要重新输入信息或使用繁琐的数据传送实用程序。Windows还具有DDE（动态数据交换）和OLE (对象链接和嵌入）功能。在DEE中两个或更多的应用程序可以被链接。使用这种方法，在一个应用程序中产生的数据可以自动地进入其他的程序。OLE类似于DEE在应用程序之间链接数据。另外，OLE允许接收数据应用程序可以直接访问建立这个数据的 应用程序。
Windows NT—Windows NT is an operating system designed to run on a wide range of powerful computers and microcomputers. It is a very sophisticated and powerful operation system. Developed by Microsoft, Windows NT is not considered a replacement for Window. Rather, it is an advanced alternative designed for very powerful microcomputers and networks. Windows NT has two major advantages when compare to Windows:
Windows NT它是一种可以在很大泛围内的功能强大的计算机和微型计算机上运行的操作系统。它是非常复杂和功能强大的操作系统。Windows NT由微软公司开发，并不是为了替代确切地说，它是设计给功能非常强大的微型计算机和网络的另外一个可供选择的高级（操作系统）。Windows NT和Windows相比较具有两个主要的优点：
Multiprocessing It is similar to multitasking except that the applications are run independently at the same time. For instance, you could be printing a word processing document and using a database management program at the same time. With multitasking, the speed at which the document is printed is affected by the demands of the database management program. With multiprocessing, the demands of the database management program do not affect the printing of the document.
多道处理除了应用程序是同时独立运行之外，它类似于多任务。比如，你可能正在打印字处理文档并且同时在使用数据库管理程序。在这种多任务操作情况下，文件打印的速度会受到使用数据库管理程序这一要求的影响。使用多道处理要求数据库管理程序并不影响打印文档。
Networking In many business environments, workers often use computer to communicate with one another and to share software using a network. This is made possible and controlled by special system software. Windows NT has network capabilities and security checks built into the operating system. This makes network installation and use relatively easy.
网络在许多商业环境中，工作人员经常使用计算机相互进行交流，并且通过网络共享软件。这是可以通过专门的系统软件来实现和控制的。Windows NT具有网络功能和嵌入到操作系统内的安全检测功，这使得网络安装和使用相对容易。
OS/2 OS/2 stands for Operating System/2. It was developed jointly by IBM and Microsoft Corporation. OS/2 has many similarities with Windows NT. It is designed for very powerful microcomputers and has several advanced features. Some of its advantages over Windows NT include:
OS/2代表操作系统/2。它是由IBM和微软公司联合开发的。OS/2和Windows NT具有许多相似之处。它是设计给功能强大的微型计算机的，并且具有几个先进特点。它优于Windows NT的一些优点包括：
Minimum system configuration Like Windows NT, OS/2 requires significant memory and hard disk space. However, OS/2 requires slightly less.
最小的系统配置 像Windows NT一样, OS/2要大的内存和硬盘空间。然而，OS/2需要的较少。
Windows application Like Windows NT, OS/2 does not have a large number of application programs written especially for it. OS/2 can also run Windows programs, but it runs these programs slightly faster than Windows NT.
窗口应用 OS/2和Windows NT一样，没有很多专门为它编写的应用程序。OS/2同样可以运行程序，但它运行这些程序的速度比Windows NT更 快一些 。
Common user interface Microcomputer application programs written specifically for Windows NT, as well as for OS/2, have consistent graphics interfaces. Across applications, the user is provided with similar screen displays, menus, and operations. Additionally, OS/2 offers a consistent interface with mainframes, minicomputers, and microcomputers.
共同的用户界面专门为Windows NT以及OS/2编写的微型计算机应用程序，具有一致的图形界面。在应用程序里，提供给用户类似的显示、菜单和操作。此外，OS/2为大型机、小型机和微型机提供一致的界面。
Macintosh Operation System —The Macintosh Software, which runs only on Macintosh computers, offers a high-quality graphical user interface and is very easy to use. Apple Macintosh System 7.5 designed for Apple computers using Motorola's PowerPC microprocessor, is a significant milestone for Apple. It is a very powerful operating system like Windows NT and OS/2. System 7.5 has network capabilities and can read Windows and OS/2 files. It has several advantages:
Macintosh操作系统它仅运行在Macintosh计算机上，提供高质量的图形用户界面，并且很容易使用。Apple Macintosh System 7.5是为使用Motorola's公司的PowerPC的微处理器的Apple计算机设计的，对于Apple机来说是一个重要的里程碑。它像Windows NT和OS/2―样是功能强大的操作系统。System 7.5具有网络功能并能读出Windows NT和OS/2的文件。它具有几个优点：
Ease of use The graphical user interface has made the Macintosh popular with many newcomers to computing. This because it is easy to learn.
容易使用图形用户界面使得Macintosh在许多计算机新手用户中普及，这是因为它容易学习。
Quality graphics Macintosh has established a high standard for graphics processing. This is a principal reason why the Macintosh is popular for desktop publishing. Users are easily able to merge pictorial and text materials to produce nearly professional-looking newsletters, advertisements, and the like.
高质量的图像Macintosh已经建立了髙标准的图像处理，这就是为什么Macintosh在桌面印刷系统流行的主要原因，用户可以很容易地将图片和文字材料组织成比较专业的通信稿、广告等。
Consistent interfaces Macintosh applications have a consistent graphics interface. Across all applications, the user is provided with similar screen displays, menus, and operations.
一致的界面Macintosh应用程序具有一致的图形界面。在所有的应用程序中，提供给用户相似的屏幕显示、菜单和操作。
Multitasking Like Windows, Windows NT, and OS/2, the Macintosh System enables you to do multitasking. That is, several programs can run at the same time.
多任务像Windows, Windows NT和OS/2 —样，Macintosh系统使得你实现多任务，即几个程序可同时运行。
Communications between programs.The Macintosh system allows applications programs to share data and commands with other applications programs.
程序之间的通信Macintosh系统允许应用程序之间共享数据和命令。
Unix—Unix was originally developed by AT&T for minicomputers and is very good for multitasking. It is also good for networking between computers. Unix initially became popular in industry because for many years AT&T licensed the system to universities for a nominal fee. It is popular among engineers and technical people, with the arrival of very powerful microcomputers, Unix is becoming a larger player in the microcomputer world. Unix can be used with different types of computer systems, that is, it is a portable operating system. It is used with microcomputers, minicomputers, mainframes, and supercomputers. The other operating systems are designed for microcomputers and are not nearly as portable. It also has the advantages of multitasking, multiprocessing, multiuser, and networking.
Unix它起初是由AT&T为微型机开发的，非常适于执行多任务处理。它也适合于计算机之间的网络链接。由于多年来AT&T一直将系统以象征性的费用提供给大学使用。因此，Unix起初就在工业领域很普及。它在工程师和技术人员中很普及，随着功能强大的微型计算机的到来，Unix正成为微机世界的大玩家。Unix可被用于不同类型的计算机系统，也就是说它是便携式的操作系统。它可用于微型机、小型机、大型机和巨型机上。其他的操作系统被设计用于微型机上且几乎不可移植。Unix也具有多任务、多道处理、多用户和网络功能的优点。