5 Fundamentals of Computer Software[精].ppt

Unit 5 Fundamentals of Computer Software Computer Software System Computer software, or just software is a general term used to describe the role that computer programs, procedures and documentation play in a computer system. 计算机软件（简称软件）是一个通用术语， Software includes things such as websites, programs or video games, that are coded by programming languages like C or C++. 软件包括用C或C++之类的编程语言编写的网站、程序或视频游戏等。 Software is sometimes used in a broader context to mean anything which is not hardware but which is used with hardware, such as film, tapes and records. At the lowest level, software consists of a machine language specific to an individual processor. 从最底层来说， At the lowest level, software consists of a machine language specific to an individual processor. 从最底层来说， Software is an ordered sequence of instructions for changing the state of the computer hardware in a particular sequence. 软件是一组有序的指令序列， It is usually written in high-level programming languages that are easier and more efficient for humans to use (closer to natural language) than machine language. 它通常使用高级语言编写， High-level languages are compiled or interpreted into machine language object code. Software may also be written in an assembly language, essentially, a mnemonic representation of a machine language using a natural language alphabet. Assembly language must be assembled into object code via an assembler. 汇编语言必须通过汇编程序汇编成目标代码。 Practical computer systems divide software systems into three major classes: system software, programming software and application software. 实际的计算机系统将软件系统分为三个主要类别： 系统软件、编程软件和应用软件。 SYSTEM SOFTWARE. System software helps run the computer hardware and computer system. It includes a combination of the following: device drivers operating systems (OS) servers utilities windowing systems As shown in Fig. 5-1, the purpose of systems software is to unburden the applications programmer from the often complex details of the particular computer being used, i