1. Chapter 6 System and Application Software
Introduction
Software is the collection of computer programs and related data that provide the instructions that tell a computer what to do.
Software is intangible, meaning it “cannot be touched”.
Two types of Software
1.System Software
2.Application Software

2. System Software
Refers to the files and programs that make up your computer’s operating system.
They provide and maintain a platform for running application software.
System software runs at the most basic level of your computer, it is called “low-level” software.
Most important types of System software are:

3. Computer BIOS and device firmware:
Which provide basic functionality to operate and control the hardware connected to or built into the computer.
Utility Software:
Which helps to analyze, configure, optimize and maintain the computer like file manager, Anti-virus and disk cleaners.
Operation System:
Is a program to run other programs on a computer
Is the most important program for computer.
Is considered the backbone of a computer, managing both software and hardware resources.

4. Operating system are responsible for everything form the control and allocation of memory to recognizing input from external devices and transmitting output to computer displays.
They also manage files on computer hard drives and control peripherals like printers and scanners.
It is an interface between your computer and the outside world.

5. OS provides an interface to monitor, keyboard, mouse and other parts using what is referred to as “drivers”.
Example: When you install a new printer or other piece of hardware, your system will ask you install more software called a driver(like video card, sound card,etc).

6. Example for Operating System Windows 7, Windows Vista, Windows 2003, Windows XP, Windows 2000, Linux, Unix and Mac

7. Programming Languages
Programming Languages are syntax, grammar and symbols that are used to give instructions to a computer.
i.e, it is a language designed to describe a set of consecutive actions to be executed by a computer.
It is a practical way for us to give instructions to a computer.

8. Generations of Programming Languages
First Generation Language (or) Machine language
It is a computer(machine) language.
It is the lowest level programming language and the only language the computer can understand.
All the commands and data values are given in zeros and ones.

9. 2. Second Generation Languages (or) Assembly Languages
These are symbolic programming languages that use symbolic notation to represent machine language instructions.
They are also called low-level languages because they are so closely to the machines.

10. 3. Third Generation Languages (or) High Level Languages
Somewhere between natural languages and machine languages.
They were developed to make the programming process more efficient.
Examples: C,C++, Visual Basic, FORTRAN, COBOL
4. Fourth Generation Languages:
These languages are easy to use and more like natural languages.
Example: SQL(Structured Query Language)

11. 5. Fifth Generation Languages:
Referred to as Object Oriented Languages.
In these languages, a program is no longer a series of instructions, but a collection of objects.
These objects contains data and operations(instructions).
These objects are created by the class concept.
Examples: C++, Java, Ada and SmallTalk.

12. Except First Generation Languages (Machine Language), all languages need one of the following translators to convert them to the machine language.
Assemblers: are programs to convert an assembly language(source code) into a machine language(object code or target code).

13. 2. Compilers:
Are programs which reads a source program created by a programmer, and then converted it into a set of instructions known as the object code or the machine code.
The object program is in a form that a computer can understand and execute directly.

14. Application Software
Application software is the set of programs necessary to carry out operations for a specified application to achieve certain tasks.
There are two main categories
Customized Application Software:
This type of software is developed and designed in stage by stage processes(tailor-made software).
2. General Application Software:
This type of software is developed keeping in mind the general requirements for carrying out a specific task.

15. Popular Application Software
MS-Office Suite:
Is a collection of software applications made by Microsoft Incorporation, like MS-Word to create documents, MS-Access to create databases, MS-Power point to create presentation, MS-Excel to create spreadsheets…etc
2. Macromedia Flash:
It is a multimedia platform used to add animation, video and inter-activity to Web pages.
Flash is frequently used for advertisement and games.

16. Popular Application Software
3. Adobe Reader and Photoshop:
Adobe Reader is the global standard for electronic document sharing.
It is the only PDF file viewer that can open and interact with all PDF documents.
Adobe Photoshop is used to create, view, edit, organize, share and print photos and pictures.

17. Popular Application Software
4. Sound/Video Players:
It is a set of application or software programs that are used to play a digital sound and video with various formats.
Examples: Windows Media Player, Real Player, QuickTime, VLC Media Player, Winamp Media Player, Crystal Player…etc

18. Introduction to Databases
A database is a set of data that has a regular structure and is organized in such a way that a computer can easily find any desired information
A database management system (DBMS) is a software that has been created to allow the efficient use and management of databases.
Example: MS-Access and ORACLE

19. Database Model
It is a theory or specification describing how a database is structured and used (like: Hierarchical DB model, Network DB model, Relational DB model, Entity-relationship, Object-relational DB model, Object DB model)
Relational DB model:
is the most popular model of database
it is the way of organizing data in a way that appears to the user to be stored in a series of interrelated tables

20. Relational Database Model
data are structured into tables (i.e., "relations") consisting of rows and columns.
Each row contains a single record comprised of individual data elements (or "attributes") organized in columns containing elements of the same kind according to the rules defined for that column.

21. Relational Database Model - Example

22. Benefits of Relational Database Model
The benefits of a database that has been designed according to the relational model are numerous.
Some of them are:
Simplicity
This provides a more simple structure than those that were being before it. The table structure is an intuitive organization familiar to most user.
Relatively easy for users to understand.
Easy to retrieve, insert, update and delete data from tables by using SQL (Structural Query Language), this is an easy and human readable language

23. Benefits of Relational Database Model
Have an excellent security; a relational database supports access permissions, which allow the database administrator to implement need based permissions to the access of the data in database tables.
Flexibility: The relational database model is naturally scalable and extensible, providing a flexible structure to meet changing requirements and increasing amounts of data.

24. Relational Database Design Process
1. Analysis of Data Requirements and Define the Objects:
analyze data requirements by determining the purpose of the database and how it is to be used
This tells you what information you want from the database
From that you can determine the subjects and facts you need to store about each object

25. Relational Database Design Process
2. Design the data structures(tables, fields, keys…etc):
In this step we design tables; each table should represent only one thing
For example, entities(tables) in "Company Database" might be: Employee, Departments, Projects…etc
Tables are made up of rows (records) and columns (attribute).
The intersection between row and column represent the field(attribute) value.

26. Relational Database Design Process
The column (or combination of columns) in a table with unique value is referred to as primary key. NULL values or empty is not allowable values for the primary key.
We indicate the primary key in the table by underlining the column name
Key can be simple or composite. A simple key is a key made up of one column, whereas a composite key is made up of two or more columns.

27. Relational Database Design Process

28. Relational Database Design Process
3. Discern(identify) Relationship:
create relationships that join together multiple tables in a database.
A foreign key is a column in a table used to reference a primary key in another table. The foreign and primary keys may be with the same column name or not, but they must be the same domain (data type and range of values)

29. Relational Database Design Process
The relationship could be created between two tables (binary relationship) or three tables (ternary relationship) or more (n-ary relationship).
Many employees works_on one department.
One employee manage one department.
** manage and works_on represent the relationship name.

30. Relational Database Design Process
In the above figure, there are two relationships between employee and department tables. Let's say that we choose Dnumber as the primary key for department table; Dnumber is considered a foreign key in employee table.
And we choose Emp_ID as the primary key for employee table; Manager_ID is considered a foreign key in department table.

31. Relational Database Design Process
These tables can be related in one of three different ways: one-to-one(1:1), one-to-many (1:M or M:1) or many-to-one, and many-to-many (M:N). These ways called the cardinality of relationship.

32. Relational Database Design Process

33. Relational Database Design Process
4. Normalization:
When designing databases you are faced with a series of choices. How many tables will there be and what will they represent? Which columns will go in which tables? What will the relationships between the tables be?
The answer to each of these questions lies in something called normalization.
Normalization is the process of simplifying the design of a database so that it achieves the optimum structure.

34. Relational Database Design Process
5. Create the application:
This step uses the DBMS to store and manage tables and relationships by computer, to make the database ready to use by insert, delete, and update data and to retrieve information easily, quickly and accurately

35. Relational Database Design Process