Module 1 (hardware)

• Input units : Any device that you use to pass data to the computer

Examples : keyboard – mouse – scanner – camera – microphone

• Storage units : it’s where computer saves data

The history and evolution of storage units

- first was 8 inch and 51/4 inch floppy disk made from cartoon

- Then 31/2 inch floppy disk made from magnetic

- Then CD and DVD we get its data from scanning the lezar

- Then USB and SD CARD was so small to hold and take it any where

- the least thing we reached so far is the CLOUD like (google photo-tera box app)

- The names of the storage unit (Arrange from largest to smallest)

Yottabyte > Zettabyte > Exabyte > Petabyte > Terabyte > Gigabyte > Megabyte > Kilobyte >
Byte > bit

- Magnetic storage media (31/2 inch floppy disk)

- Optical storage media(CD and DVD)

- SSD perform about 12 times faster than the fastest HDD

 • Processing units (Physical parts of the processing components)
- Central Processing Unit (CPU)
- Random Access Memory (RAM) currently being processed

• Output Units (the devices that gets the information out of the computer to you)

- Examples : monitor – printer – speaker – plotter

………………………………………

Module 2 (software)
• Operating system (OS) : system software that manages computer hardware and
software resources and provides common services for computer programs

Operating system function

Computer user application Operating system Device drives System software

Computer hardware

• History and development of Operating systems

o Names of modern Operating Systems From Popular Companies

( macOS - Android OS -Windows - iOS - Linux )

 Main components of an operating system

1. File Management

- Path
C : \ Documents \ AIU \ Building . jpg

Partition folders File Extension

• Common file systems ( FAT32 – ExFAT)

• Proprietary File systems

Apple IOS : Uses HFS+ file system

Microsoft Windows : Uses NTFS file system

Google Android : uses EXT4 file system

2. Process Management

Application launch Application running Application close

1- Process created 1-Resources maintained 1-Process terminated

2-Memory allocated 2-Dynamic reallocation 2-Memory deallocated
3-Processor workload 3-application demands 3-Processor workload
dedicated during runtime freed
 3. I/O Device Management

The computer contains lots and lots of smaller electronic hardware units so
The Contron unit in the processor make all these units work together

disks USB monitor CPU

common bus

shared memory

4. Network Management (Networks helps connecting computers to various network

resources available, in addition to connecting computers to each others)

- Local area network (LAN) : is a network that is confined to a relatively

small area (school – lab – building )

- Wide area network (WAN) : connect networks in larger geographic areas

(Cairo – Africa – the world )

- Identifying network devices

Modem : connect to the internet

NIC : though it the CASE connected to the internet by a wire

Repeater : Expand the internet signal

Hub : take the data from a source and distribution it to other devices
 Switch : take the data from a device and give to another

Router : connect the device to the internet

Bridge : connect more than local area network to eachother

Gateway : connect a whole foundation or country to the internet

5. Memory management
1. Allocate and de-allocate memory before and after process execution
2. keep track of used memory space by processes.
3. minimize fragmentation issues.
4. proper utilization of main memory
5. maintain data integrity while executing of process

6. Security Management

1- Active attacks: attempts to alter system resources or affect their operations

(someone who does it)

▪ masquerade : Impersonating someone ( ‫) انتحال شخصية شخص ما‬

▪ modification of messages : Messages hacking

▪ Replay : Transferring messages from one person to another
▪ Denial of service : hacking the system

2- Passive attacks : a virus that spies )‫ (يتجسس‬to take information

 3- Malware : the viruses

It can ( block access to the network or parts of the network - install other malware -

secretly copy data and transmit it - disrupt the system )

▪ Ransomware : a virus that closes all the files until you pay

4- Phishing : through it most of the attacks happen (the advertisements) and Fake
emails ) ‫ ادخل رقمك الستالم الهدية‬16 ‫( شغل مبروك كسبت ايفون‬

BIOS AND Booting : the downloading before opening the computer

• User management :
▪ Administrator : The system Admin that has all the required privileges to
add/edit/delete all the other users.
▪ Standard : a normal user that can’t manage any other user account but his own
account

Operating system licensing :

▪ Retail : that is a single user copy

▪ OEM : sold to a computer hardware system ( Dell – lenovo – acer – atc … )
▪ Volume : that is sold for large business corporations

Operating system Virtualization :

▪ Guest : that is the system being hosted inside your original physical system.
▪ Virtualization layer : creating the environment that simulates a physical
computer and make it available to guest operating system
 ▪ Host : that is the actual physical system and resources that hosts the virtual
guest

Most important usages of virtualization technology :

▪ Run Old or Incompatible Software

▪ Develop Software for Other Platforms
▪ Handle Potential Malware Safely
▪ Tear Apart Your System

• Operating system virtualization products

▪ Oracle virtualbox
▪ VMWARE Workstatio

• Applications : written by professional developers using programming languages like

(C++, Java, Visual Basic, Python, PHP, C#, etc...)

• Application installation
1. most application ships in installation packages.
2. instructions needed to successfully prepare the application to be installed and launched later
3. The installer also saves each change it makes during the installation process, so it can revert it when
the user decides to Uninstall the application
 • Application layered architecture

Presentation layer : what user sees when the application is launched

Business layer : where the calculations and data processing happens

Persistent data layer : where the data goes when it gets loaded

Database : the application storage, where all the input and processed
output is saved on the device’s permanent storage , user is never allowed to
access this layer directly

• Application license
▪ Freeware : is free
▪ Shareware : free at first then paid
▪ Commercial : is paid

▪ One-Time Purchase: (Microsoft windows)

▪ Subscriptions: (Spotify, YouTube Premium, Netflix)
▪ In-App Purchases : (Minecraft, PUBG, COD)
▪ Pay -As -You -Go : (Amazon , Noon )
 Module 3
• Database:
▪ an organized collection of structured information or data stored in a computer system
▪ it modeled in rows and columns in a series of tables to make processing and data
querying efficient
• DBMS : creating , storing , maintaining , organizing , updating and deleting the
data
➢ Features of DBMS
- data modeling : ( your name – your number – your identity - etc.. )
- data storage and retrieval : (responsible for storing and retrieving data )
- concurrency control : (multiple users can access the data without
conflicting with each other)
- Data integrity and security : (check the security constraints if the rules of the
data is right and who can access the data )

• Backup and recovery : backing up and recovering the data

• SQL : for writing and querying data

• Database advantages in our life :

you’d have to fill your introduction only once, then the restaurant would save it using a
database , The next time you call the restaurant, it will never ask you again for your information,
instead it will jump directly to the order, as your data is already saved

• The foundation behind Databases :

- databases existed since the first human being walked the earth
 ▪ SET theory

If the student who study IT called set A , and the all student of the uni called set B ..
students who study the IT called predicate

▪ The Predicate Logic

A predicate is a property or expression that is true or false

For example : if we asked the IT students if they study IT answer is true

▪ QUERY : The goal of any database is to bring you the data once you ask

- SELECT : the fields (What parts of the data you need to select)
- FROM : the table (What table you want to get the data from)
- WHERE : the predicate (The exact needed records to get and where to find it)

Relational DBMS : is considered to be relational because it allows users to define

relationships within and between the various tables using keys.

primary and foreign keys : These relationships help structure and organize the
database and limit the amount of data duplication

• primary key : unique for every one , can’t be duplicated

• foreign keys : it can be duplicated if the relation allowed

Keys :

▪ To build an efficient database system, any table record must be well defined using keys.
▪ the method that allows the database engine to lookup the referenced data across multiple
related tables
 Identify each record in table Define Relation between the tables

Database

KEYS

Establish relation between the tables Enforce referential integrity

Relationship types :

▪ One-To-One : Each record in Parent table is related to only one record in Child table

▪ One-To-Many : Each record in Parent can be related to one or more records in the Child table
▪ Many-To-Many :
- Each record in the Parent table can be related to one or more records in the Child table
- and each record in the Child table can be related to one or more records in the Parent table, usually this
relation type is broken to 2 one-to-many relationships by using an intermediate table
 • Data Normalization :

Table: Appointments
Table: Patients
PatientId
PatientId

FirstName
Primary Key AppointmentId foreign key
AppointmentDate
lastName
TreatmentType
Age
ToothNumber
Email
Status
PhoneNumber

One to many

Data Normalization
- Reduce redundancy among data
- Increase the overall performance of the data transferer
- Keeps data integrity as data needs to be changed at one place only if needed.
- Keeps data consistency as data is stored only once and referred to as needed
 ➢ The difference between database and data ware housing :

• Database : used for processing and storing current data

• Data warehousing :

▪ is used to build historical data from multiple data sources

▪ Data from different sources are brought to a single location
▪ then converted into a format that the data warehouse can process and store

For example : a company stores data about its customers, products, employees,
salaries, sales, and invoices

…………………………………………..
 Module four
computer program : set of instructions in a programming language , written by
professional applications developer

Source code Native Machine

language application
Written By the compiler
That the CPU can executable
developer understand

Programming started years before the invention of computers

• An algorithm :
- Level
Must provide definite instructions
- Must be carried out in the same order
- Must be generic
- Must terminate at end

Flowchart symbols :

Start / end

Arrows

Input / output

Process

decision
 ▪ Pseudocode : DOES NOT REPRESENT A PROGRAMMING LANGUAGE
▪ but it is the simplest form of code that describes the abstract solution to perform a task of
solve a problem

▪ Decision making :
Programming aims to make the computer takes a decision based on a condition
that compares two operands and outcomes either True or False

Stack memory : currently ( frame by frame ) – small size

Heap memory : not currently ( the total game ) – bigger size

Stack memory Heap memory

• Data can be added to and • Data can be stored and removed
Deleted only from the top of it In any order

• It is stored directly • It is stored indirectly

• Variables can’t be resized • Variables can be resized

• Its access is fast • Its access is slow

• Its block allocation is reserved • Its block allocation is free and

In LIFO done at any time

• It can be accessible only to the • It can be accessible to all the

Owner threads Threads

• It can be used by one thread of • It can be used by all the parts

Execution Of the application

• Local variables get wiped off • Using a special system process

Once they lose the scope
Value types: are stored directly in the Stack memory

int, double and bool are example of Value types

Reference types : stores its value in the Heap area as their values usually large compared
to Value types.

String , Class and Object are examples of Reference types

By : Eslam safwat

‫معلش مكملتش حتة البرمجه عشان انا ف كومبيوتر ساينس ف بالنسبالي حاجه تافهه‬