Computer Software Unit C

Software Categories System Software Application Software

Software Categories Application Software helps you carry out tasks- such creating documents, editing photographs- using a computer. System software helps your computer carry out basic operating functions. Software consists of computer programs, support programs, and data files that work together to provide a computer with the instructions and data necessary for carrying out a specific type of task.

System Software OperatingSystemsDeviceDriversUtilitiesProgrammingLanguages DOS Windows Linux UNIX Mac OS

Application Software DocumentProduction SpreadsheetSoftware Accounting & Finance MathematicalModeling Statistical Entertainment DataManagement Graphics Music VideoEducational Reference

Software Topics Computer program –main executable program (.exe) Support module –called by the program (.dll) Data module –Example: a dictionary file or a file that is not supplied by the user

How Computers Interpret Software A programming or computer language provides tools that a programmer uses to create software. These languages help the programmer to produce a list of instructions called source code. The high-level languages are similar to human languages and produce programs that are fairly easy to test and modify. Main programming languages include C++, Java, COBOL, and Visual Basic,

How Computers Interpret Software A computer’s processor interprets the programmer’s instructions, but the processor can only understand machine language. Instructions written in a high-level language must be translated into machine language before a computer can use them. There are two types of translators: compilers and interpreters.

How Computers Interpret Software An interpreter coverts one instruction at a time while the programming is running.

How Computers Interpret Software A compiler converts high-level instructions into a Compiled program, which is a new file containing machine language instructions. A complier translate all the instructions in a program as a single batch, and the resulting machine language instructions are placed in a new file. This is the object code.

Operating Systems Interacts with application software, device drivers & hardware to manage computers resources

Exploring Windows Starting programs Creating and saving a document with a text editor. Creating files or directories Moving and copying files with my computer Deleting an restoring files

Operating System Categories A single-user operating system is designed to deal with input, output, and processing requests from one user. PCs and handhelds A multi-user operating system is designed to deal with the input, output, and processing requests from many users at the same time. mainframes or centralized computer processing A Network/Server operating system provides communications and routing services that allow computers to share data, programs and peripheral devices. Desktop: desktop or notebook PC; single-user, but could handle networking

Operating System Categories A multitasking operating system provides process and memory management services that allow two or more computer programs to run simultaneously. Microsoft Windows is installed on over 80% of the world’s PCs. Mac OS The UNIX operating system was developed in 1969 at AT&T’s Bell Labs. It gained a good reputation for its dependability in multi-user environments. In 1991, Linus Torvalds developed the Linux operating system based on a version of UNIX. It is very good and free! DOS

Document Production Software Use to compose, edit, design, print or electronically publish documents Types –Word processing (Word) –Desktop publishing (PageMaker) –Web authoring (Front Page)

Document Production Elements Formatting Page Layout Headers/FootersClipartTables Frames Spell check Word wrap Margins Styles

Spreadsheet Software Use for numerical calculations and graphs Rows and columns Worksheet, cell, cell references Cells can contain –Values –Labels –Functions –Formulas

Spreadsheet Software Formulas vs. functions Relative vs. absolute cell referencing Automatic recalculation Templates What-if analysis

Data Management Software Use to store, find, organize, update and report information File management software –Structured or flat file –A record contains multiple fields

Data Management Software Database Management Software (DBMS) –Database (collection of related files) –Relational (tables with records & fields) –Object-oriented (records manipulated using methods) File structure –Fields and data types SQL (Structured Query Language) –Natural query language –Query by example (QBE)

Graphics Software Use to create, display, modify, manipulate and print graphics Paint software: realistic art and photos Photo Editing software: simplifies common editing tasks Drawing software: uses vector figures & shapes to create “cartoon-like” images.

Graphics Software 3-D Graphics software: create wireframes and then cover with a texture CAD (computer-aided design): 3-D software designed for architects and engineers Presentation software: creates electronic slides like these

Business Software Accounting & Finance –Personal finance –Tax preparation –Small business accounting Vertical Market –Hospitals, construction, schools Horizontal Market –Generic like payroll –Project management Groupware –Help collaboration on group projects

License vs. Copyright Software License: a legal contract that defines the ways in which you may use a computer program. Copyright: a form of legal protection that grants the author of an original work an exclusive right to copy, distribute, sell and modify that work. Software piracy For contract to take effect: –Open a shrink-wrap license product –Agree to an installation agreement

Types of Copyright Protections Shareware: try before you buy on the honor system Freeware: no fee - can use, but not alter or sell Open Source: uncompiled source code that can be changed - sold or free Public Domain: can be copied, altered and resold

Computer Software End