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Tonga Institute of Higher Education IT 245 Management Information Systems Lecture 5 Software Application Software & System Software Versatile Machine • Computers have become the most versatile machines man has ever created • The reason is that software allows a computer to perform an infinite variety of tasks. Computer Software • When computers first started, software was defined as anything that was not hardware; anything that wasn’t real • Some text book defines software: – A set of instructions to be used in a computer to get a certain result • Example, Microsoft Word is called software, but the document file that you create is not software. That is data or a document file. Types of Software • “Application” software are programs that the user runs. These could be Microsoft Word, Excel, a video game, a DVD video player • “System Software” is the software that runs the operating system. It includes all the utilities and helper programs that run the operating system Computer Programs • Programs are a set of detailed, step-bystep instructions that tell a computer how to solve a problem or carry out a task • Programs are written in a computer language that the computer can understand. • Typical languages might be called C, C++, Java Computer Programs Programming languages use different words and ideas to tell a computer what to do Let’s look at what this program does How software works (more) • A CPU understands a special machine language only • Thus, when you write a program in C++, Java, etc, it must be translated into this special machine language • A “compiler” will turn your programming code into machine language so it will run correctly How software works Code is converted from a high level language like C++ into machine language so it can run on the computer Interpreters • Some programming languages, called “scripting languages” don’t use compilers • These use “interpreters” • The difference is that to run the program, you run the interpreter first, and tell the interpreter to run your program (your script that you made) • Examples: JavaScript, Perl Interpreters • Interpreters are useful because they allow a program to run on any type of computer • When you compile a program, it changes into the binary language that only works on one kind of processor • This means your program cannot run on a computer with a different CPU or operating system • An interpreter will change the code automatically to the right kind of machine language so that the programmer only needs to write the program once. A running program The steps to run a program 1. 2. 3. 4. 5. 6. 7. Double click on a program to start Your clicking opens a compiled executable file stored on the hard drive The instructions (code of the program) is loaded into RAM and then sent to the CPU The CPU will run the program and ask the user to do something. When you are done with the program, you close it and the CPU stops executing the program The program instructions are erased from the RAM The CPU is ready for another program Overview of Computer Software Application Software • End user applications • Before we start lets look at an example of the changing world of software in business Software – Real Case 1 Program components of the top 4 software suites. Trends in Computer Software • Trends in software is toward multipurpose, web-enabled expert-assisted packages with natural language and graphical user interfaces. Application Software for End Users • Can be subdivided into two Categories – General purpose Category – Application Specific Category Application Software for End Users • Application Specific - are available to support applications of end users in business and other fields – such as managerial, professional and business uses • such as transaction processing, decision support, accounting, sales management, investment analysis and electronic commerce Application Software for End Users • General Purpose – programs that perform common information processing jobs for end users. Such as word processing program, spreadsheet program, database program, graphic programs which are popular with microcomputer users for home, education, business, scientific and many other purpose. Software Suites & Integrated Packages • Software Suites – comes bundled together as one software such as MS Office, Lotus Smart Suite etc. • Integrated Packages – combines some of the functions of several programs into one software package, such as MS Works, Workplace etc. – This have proven that they offer enough functions and features for many computer users while providing some of the advantages of software suites in a small package. Other Software • Web Browsers – powerful and featurerich sometime called universal client – install on the workstations of all the clients (users) in a client/server networks throughout an enterprise. • Electronic Mail. • Word Processing • Desktop Publishing • Electronic Spreadsheets Other Software • Database Management – Database Development – Define and organize the content, relationships and structure of the data needed to build a database – Database interrogation – Access the data in a database to display information in a variety of formats, – Database maintenance – Add, delete update and correct data in a database. – Application Development – Develop prototypes of Web pages, queries, forms etc. Other Software • Presentation Graphics and Multimedia • Personal Information Manager (PIM) – for end user productivity and collaboration • PDA personal digital Assistance GroupWare • Collaboration Software – software that helps workgroups and teams of general purpose application group assignment. Business Software • Some of the major application software categories in an EBusiness enterprise System Software – Computer System Management • System software consist of programs that manage and support a computer system. • Try Software Case 2 System Application Interactions System Application Interactions • • • • • System Development Program Operating System (OS) User Interface GUI Command Driven menu Operating Systems • The system software acts as the master controller for all that takes place on a computer • Every type of computer has an operating system that defines many operations • Examples: How many programs can run at once? What do the borders around programs look like? Can the computer connect to the internet? OS • The operating system will coordinate all activities that occur in a computer • If, for example, you want to print a document, – 1. Tell your application to print – 2. The application tells the operating system that it wants to print – 3. The OS talks to the printer device, and the document gets printed Basic Function of OS OS and resources • The operating system manages system resources. A resource might be the CPU, RAM, space on a hard drive • The OS must ensure all programs can get access to these resources when they need to. – What if two programs both want to print? – The OS will manage the resource, decide who prints first and make the other program wait The OS and Memory • One of the most important jobs an OS has it to manage memory (RAM). • If more than one program is running, the two programs are both using the RAM. • How do we make sure that the programs don’t use each other's memory?? • The operating system gives each program running it’s own different “memory space.” • Sometimes the OS makes mistakes (errors from programmers) and programs will use memory from another program. The computer usually will crash when this happens!! Internal OS • Because different programs might need the same resource (memory, printer, speakers), the OS must decide when and how each gets its turn • It will use “buffers” and “queues” to accomplish this. • A buffer is like a line of things waiting to happen. The OS can finish with one, and then take the next in line Buffer/Queue Program 1 1st Program 2 Program 3 2nd 3rd OS and GUI • An OS will also usually determine the “look and feel” of a computer. • With the graphical user interface (GUI) the OS can change how menus, windows and icons appear to the person using the computer GUI and Text interface. OS changes the way it looks OS • The operating system usually lives on the hard drive because it takes up a lot of space. • The most important part of the OS is the “kernel.” The kernel accomplishes the most important tasks, like managing files and using memory. • You can’t close or exit the kernel. It is always running. It’s what makes your computer and operating system run. Types of OS • Single User – Only allows one person to use a computer at a time • Multi-User – more than one person can execute programs on the computer • Multi-User don't mean many people can use the same keyboard and monitor at the same time, but instead there are ways, by using the network, to run programs on the computer More OS Categories • Multi-tasking – this means the OS can run more than one program at a time. All current Operating Systems are multi-tasking and allow you to do more than one thing at once. • If you talk on a cell phone and drive at the same time, you are multi-tasking (doing more than one thing at a time). A computer is very good at this More OS categories • Server OS – this will run all the responsibilities of a server. It is most useful if it runs a network • The main difference between a server and a regular computer is that a server runs certain programs (called services) that provide things for the client. • Any computer can be turned into a server with the proper programs. • Desktop OS – used on client or desktop machines. Available Operating Systems • Microsoft – DOS, Windows 3.1,Windows95, Windows98, Windows 2000, Windows XP • Apple – Macintosh (latest called OSX) • Linux – Redhat, Mandrake, Suse, Debian • UNIX – SunOS Comparison Popular OS Application Software • • • • • • Applications let users accomplish tasks Word Processing Desktop Publishing Web authoring software Spreadsheets Accounting, Mathematical, Statistics software Other System Program • Network Management Program • Database Management System • Utilities and security programs Data management software • Data management software (databases) help organize, sort, store, and update data. • A “record” holds the data for a single entity. – If we had a database for students, a single “record” would save all the information about one student • A “field” holds one item of data. – The students name would be a field. So would his age, or address Databases • Database Management Software (DBMS) – this helps people sort through a lot of data. It is a piece of software like MS Access or mySQL • Most powerful DBMS use what is called a “relational” database structure. • “Relational” means that relationships can be found and created between different sets of data. – For example, you might have a set of data about students and one about classes. – If the class table saved who was in the class, you could look up and see where that student lived, using the student table. This is a relationship DBMS • So how do you use a DBMS? • There are user interfaces that help • The main way is through a programming language called SQL (Structured query language). A query is a question. • Example: You could “query” a database of students to find all students with the name Sione – The SQL statement to do that would look like – Select * from StudentInformation where firstname=“Sione” Other queries • Some advanced databases use Natural Language Queries. • This means you could just enter: – What students are named Sione? • This would work the same as the SQL query – select * from StudentInformation where name=“Sione” Graphics Software • Paint software – image editing (for fixing images) • Photo editing software – can fix photos • Drawing software – for making objects, boxes, lines • 3-D graphics • CAD software (Computer Aided Design) – used by people who make buildings, cars, anything that needs to be designed before it is built. • CAD software can make blueprints for designs Music Software • To hear music on your computer, you need a music player (like windows media player or winamp). • These players can “decode” a specific format of music into the kind needed for it to come out of speakers. • MP3 is a format of music. An MP3 player can ‘decode’ the mp3 format into one that you can hear. • There are other formats like WAV, Ogg Vorbis, WMA Software Installations • To install software you will need the “distribution disks” either CDs or floppies. • Also you need to make sure your computer has enough memory and is fast enough to run the software • This is called “system requirements” Steps in Installing Software 1. 2. 3. 4. 5. 6. Copy files from the disk (CD or floppy) Uncompress files (they are compressed to save space) Analyze computer to see if it meets system requirements Identify where operating systems files are that the program might need. For example: A MP3 Player might need to know how to use the OS to send sound to the speakers Update system files like the windows registry. The program might need to tell the OS something about itself Move files into correct place Uninstalling software • To get rid of software that you don’t want anymore first look for a uninstaller program that came with the installation of the program. • If there is not an uninstaller, go to the control panels (on windows) and look for the icon that says, Add/Remove Programs. • If you just try to delete a program, there may be many parts that are left over from the program that will take up space if not removed Uninstalling What is the Windows Registry • Microsoft computers use the “windows registry” to tie all the pieces of the computer hardware, peripherals and software together • The registry keeps track of where certain things are like printers, memory, scanners, software ‘modules’ and OS components • It also keeps track of user settings, like desktop pictures, installed programs and what programs will run when the computer starts up • It is a database of information for the Windows operating system Registry Registry Copyrights and Software • Companies try very hard to stop people from stealing software. • It is difficult because of a computer's ability to do many things • Computers make it easy to copy and duplicate anything, including software, movies and music Copyrights and Software • Companies have tried aggressively to stop “software pirating” but fail. • It is said the computer industry loses over 12 billion US dollars a year • Piracy is very bad especially in India, China, and Eastern Europe where many people are too poor to buy software Copyrights and Software • Not all software costs money • Shareware – lets you try software for a while, then asks you to pay for it to continue • Freeware – the software is totally free Copyrights and Software • People today are beginning to realize they do not need to buy software and can use free software • This software is called “open-source” - because all the code that people made is available to see and change. • “Closed-source” is what companies like Microsoft use to hide their property so people cannot change and use it improperly Open Source • Open source is mainly associated with Linux and Unix, two types of operating systems • The Linux operating system and all the programs that can be used with it are free and are open source • If a program is open source and you don’t like how it runs, you are free to change the code and make the program do something else Open Source • Because open source allows everyone to look at the code or programming, people say it is more secure and more stable. • Many people all over the world can look at the software, instead of just a few people inside a company. Summary • Operating systems • Application Software – Databases, Media players, • Installing software • The Window Registry • Copyrights and Open Source