计算机专业英语ppt课件(完整版).ppt

Unit 4 Section 2 Passage A A loader is the part of an operating system that is responsible for loading programs into memory, preparing them for execution and then executing them. The loader is usually a part of the operating system’s kernel and usually is loaded at system boot time and stays in memory until the system is rebooted, shut down, or powered off. A linker or link editor is a program that takes one or more objects generated by compilers and assembles them into a single executable program. Linkers can take objects from a collection called a library. The objects are program modules containing machine code and information for the linker. The linker takes care of arranging the objects in a program’s address space. Unit 4 Section 2 Passage A An interpreter is a computer program that translates and executes instructions written in a computer programming language line-by-line, unit by unit etc. An interpreter needs to be able to analyze, or parse, instructions written in the source language. In contrast, application software (also called end-user programs) includes database programs, word processors, and spreadsheets. Figuratively speaking, applications software sits on top of systems software because it is unable to run without the operating system and system utilities. Unit 4 Section 2 Passage A There is a lot of application software, which is often sold as part of a software suite. An application suite consists of multiple applications bundled together. They usually have related functions, features and user interfaces, and may be able to interact with each other, e.g. open each other’s files. Business applications often come in suites, e.g. Microsoft Office, OpenO, and iWork, which bundle together a word processor, a spreadsheet, etc.; but suites exist for other purposes, e.g. graphics or music. Enterprise software addresses the needs of organization processes and data flow, often in a large distributed environment. (Examples include Financial, Customer Rel