Computer Systems

Page 2: Computer System Overview

  • A computer system is made up of a mix of software and hardware parts

  • Important hardware components include the CPU, memory, storage, input/output devices, etc.

  • Examples of software include the operating system, programs, and utilities

  • Computer systems use peripherals and connect to networks

  • Security and routine maintenance are crucial

  • Computers exist in various shapes and sizes and can access cloud services

Page 4: Hardware Components

  • Hardware refers to the physical parts of a computer or electronic device

  • Hardware carries out various tasks and functions

  • Examples of hardware parts include the CPU, RAM, ROM, motherboard, input/output devices, graphics processing unit, network interface cards, optical drives, expansion cards, cooling systems, cables and connectors, and batteries

Page 9: Software Components

  • Software refers to the collection of programs, data, and instructions that enable a computer to perform tasks

  • Software is intangible and consists of code and data executed by the computer's hardware

  • Important aspects of software include the operating system, application software, utility software, and firmware

Page 11: Network Components

  • Network components are the physical and logical elements that comprise a computer network

  • These components facilitate communication and data transfer among network devices

  • Examples of network components include routers, switches, hubs, access points, modems, Ethernet cables, fiber optic cables, coaxial cables, network interface cards, wireless network adapters, TCP/IP protocols, HTTP, FTP, SMTP, DNS servers, DHCP, and domain name system servers

Page 16: Network Topology and Network Operating Systems

  • Network topology refers to the physical or logical layout of network components

  • Examples of network topologies include star, bus, ring, and mesh

  • Network operating systems are specialized operating systems designed for managing and administering network resources

Page 17: Security Components

  • Security components are elements and tools used to safeguard computer systems, networks, and data

  • They ensure the confidentiality, integrity, and availability of systems and data

  • Examples of security components include firewalls, antivirus software, encryption, authentication mechanisms, intrusion detection systems, and physical security measures

Page 18: Firewalls, Antivirus and Antimalware, IDS and IPS

  • Firewalls regulate incoming and outgoing network traffic

    • Act as a barrier between trusted internal networks and untrusted external networks

    • Based on defined criteria

  • Antivirus and Antimalware software detect, prevent, and remove malicious software

    • Viruses, worms, Trojans, spyware

  • IDS detect malicious activity or policy violations, generating alerts

  • IPS actively block or prevent detected threats

Page 19: VPNs, Access Control Systems, Authentication Mechanisms

  • VPNs provide secure, encrypted connections over untrusted networks

    • Safeguard data confidentiality and privacy

  • Access Control Systems enforce policies and permissions

    • Restrict user access to computer resources

  • Authentication Mechanisms verify user identity before granting access

    • Methods: usernames, passwords, biometrics, two-factor authentication (2FA)

Page 20: Encryption, Network Segmentation

  • Encryption safeguards data by converting it into a coded format

    • Can only be deciphered with the correct key

  • Network Segmentation divides a network into smaller segments with restricted access

    • Helps contain security breaches

    • Limits the potential impact of attacks

Page 23: Classification of Computing Devices

  • Computing devices are machines used to acquire, store, analyze, process, and publish data electronically

  • Classification based on size, capabilities, and intended use

  • Supercomputers: Extremely powerful, used for complex calculations

  • Mainframes: Large, for critical business tasks

  • Minicomputers: Used for tasks like database management, scientific research, and manufacturing control

  • Personal Computers (PCs): General use, desktops, and laptops

  • Workstations: High-performance computers optimized for specific tasks

  • Tablets and Smartphones: Portable touchscreen devices

  • Wearable Devices: Body-worn, health and notifications

  • Embedded Systems: Specialized computing devices integrated into everyday objects and systems

  • Analog Computers: Work on the principle of measuring

Page 27: Standard Organizations

  • Standard organizations define and maintain technical standards and specifications

  • Ensure interoperability, compatibility, and uniformity in the computer industry

  • International Organization for Standardization (ISO): Creates international standards for various computing topics

  • Internet Engineering Task Force (IETF): Creates and maintains internet-related standards and protocols

  • Institute of Electrical and Electronics Engineers (IEEE): Develops standards for various technology fields

  • Internet Society (ISOC): Promotes the development and use of internet standards and protocols

  • World Wide Web Consortium (W3C): Develops and maintains standards and guidelines for the World Wide Web

  • Trusted Computing Group (TCG): Develops open standards for trusted computing and security technologies

  • Open Computing Project (OCP): Develops open hardware standards for data centers

  • Distributed Management Task Force (DMTF): Develops standards for managing and monitoring computer systems

  • Object Management Group (OMG): Develops standards for object-oriented modeling and middleware

  • The Open Group: Focuses on enterprise architecture standards

Page 34: Historical Development of Computer System

  • Pre-20th Century: Mechanical computing devices like the abacus and slide rule

  • First Generation (1930s-1950s): Electronic digital computers using vacuum tubes and punched cards

  • Second Generation (1950s-1960s): Transistors replaced vacuum tubes, high-level programming languages introduced

  • Third Generation (1960s-1970s): Integrated circuits, time-sharing systems, multi-programming

  • Fourth Generation (1970s-1980s): Microprocessors, personal computers, software development growth

  • Fifth Generation (1980s-Present): Advances in microelectronics, AI, parallel processing, internet, mobile devices

  • Contemporary and Future Trends (21st Century): Cloud computing, virtualization, big data, IoT, quantum computing

Page 39: Computer Level of Hierarchy

  • Computer Level Hierarchy organizes computer systems and components into different levels or layers

  • Each level has defined duties and responsibilities

  • Enables efficient operation and management of complicated computing systems

Page 40: User Level and Application Level

  • User Level:

    • End-users interact with the computer system to perform tasks and run applications.

  • Application Level:

    • Software applications that users utilize to perform specific tasks.

    • Examples include web browsers, word processors, and games.

  • Operating System (OS):

    • Acts as an intermediary between the hardware and software.

    • Manages hardware resources, provides services to applications, and handles tasks like memory management and file I/O.

    • Examples include Windows, macOS, and Linux.

Page 41: Hardware Abstraction Level and Microarchitecture Level

  • Hardware Abstraction Level:

    • Abstracts the hardware components, making it easier for the OS to interact with different hardware configurations.

    • Includes device drivers and hardware abstraction layers.

  • Hardware Level:

    • Lowest level of the hierarchy.

    • Includes the central processing unit (CPU), memory (RAM), storage devices (e.g., hard drives and SSDs), input and output devices (e.g., keyboard, mouse, and display), and various controllers.

  • Microarchitecture Level:

    • Deals with the organization and design of the CPU and its internal components, such as registers, ALU (Arithmetic Logic Unit), and control unit.

Page 42: Digital Logic Level and Electronic Components Level

  • Digital Logic Level:

    • Uses digital logic gates (AND, OR, NOT, etc.) to build the components of the microarchitecture.

    • Creates the basic building blocks for data processing.

  • Electronic Components Level:

    • Physical layer where electronic components like transistors, capacitors, and resistors are used to build logic gates and memory cells.

  • Quantum Level (Theoretical):

    • In the realm of quantum computing.

    • Manipulates quantum bits (qubits) and quantum gates to perform quantum computation.

    • Not part of traditional computer hierarchies.

Page 43: Cloud Computing

Page 44: Cloud Computing Overview

  • Cloud computing is a technology and service model that allows users to access and use computing resources via the internet.

  • Users can rent or lease resources from cloud service providers instead of owning and maintaining physical hardware and software.

Page 45: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS)

  • Infrastructure as a Service (IaaS):

    • Provides virtualized computing resources.

    • Allows users to rent virtual machines, storage, and networking components.

    • Examples include Amazon Web Services (AWS) EC2 and Microsoft Azure Virtual Machines.

  • Platform as a Service (PaaS):

    • Offers a platform and environment for developers to build, deploy, and manage applications without worrying about infrastructure management.

    • Examples include Google App Engine and Heroku.

  • Software as a Service (SaaS):

    • Delivers software applications over the internet on a subscription basis.

    • Users access these applications through a web browser.

    • Examples include Google Workspace (formerly G Suite), Microsoft 365, and Salesforce.

Page 46: Public Cloud, Private Cloud, and Hybrid Cloud

  • Public Cloud:

    • Resources are owned and operated by a third-party cloud service provider.

    • Made available to the general public over the internet.

  • Private Cloud:

    • Resources are dedicated to a single organization.

    • Can be hosted on-premises or by a third-party provider.

    • Offers more control and security.

  • Hybrid Cloud:

    • Combines public and private clouds.

    • Allows data and applications to be shared between them.

    • Offers flexibility and scalability.

Page 47: Key Characteristics and Benefits of Cloud Computing

  • Key Characteristics:

    • On-Demand Self-Service

    • Scalability

    • Resource Pooling

    • Rapid Elasticity

    • Measured Service

    • Cost-Efficiency

    • Flexibility

    • Accessibility

    • Reliability

    • Security

  • Benefits:

    • Increased flexibility and scalability

    • Cost savings

    • Improved collaboration and productivity

    • Enhanced security and reliability

Page 48: The Fragility of the Internet

Page 49: Fragility of the Internet

  • Despite its resilience and widespread use, the internet is not immune to many forms of fragility and vulnerability.

  • Primary elements contributing to the internet's fragility:

    • Physical Infrastructure Vulnerabilities

    • Cybersecurity Threats

    • Dependency on Critical Components

    • Traffic Congestion

    • Fragmentation and Censorship

    • Privacy Concerns

    • Economic and Political Factors

Page 50: Physical Infrastructure Vulnerabilities and Cybersecurity Threats

  • Physical Infrastructure Vulnerabilities:

    • The internet relies on a vast network of physical infrastructure, including undersea cables, data centers, and network routers.

    • Susceptible to physical damage from natural disasters and man-made incidents.

  • Cybersecurity Threats:

    • Cyberattacks, including Distributed Denial of Service (DDoS) attacks, malware, phishing, and data breaches.

    • Can disrupt internet services, compromise data, and damage infrastructure.

Page 51: Dependency on Critical Components, Traffic Congestion, Fragmentation and Censorship, and Privacy Concerns

  • Dependency on Critical Components:

    • The internet depends on critical components and services provided by a relatively small number of organizations and entities.

    • An attack or failure of one of these critical components can have widespread consequences.

  • Traffic Congestion:

    • Congestion on the internet can lead to slowdowns and service disruptions, particularly during times of high demand or in regions with limited network capacity.

  • Fragmentation and Censorship:

    • Some governments and entities have implemented internet censorship and content filtering.

    • Results in a fragmented internet where access to certain websites and information is restricted.

  • Privacy Concerns:

    • Concerns about data privacy and surveillance can erode user trust in the internet.

    • Data breaches and privacy violations can lead to public outcry and regulatory actions that impact internet services.

Page 52: Technical Limitations, Social Engineering and Human Error

  • Technical Limitations:

    • While the internet was designed to be resilient, it is not invulnerable.

    • Technical limitations and design flaws can lead to issues like routing problems, protocol vulnerabilities, and outages.

  • Social Engineering and Human Error:

    • Social engineering attacks and human errors, such as misconfigurations and accidental data leaks.

    • Can lead to security breaches and data exposure.

Page 53: Environmental Factors

  • Climate change and extreme weather events can impact the physical infrastructure supporting the internet.

  • Can lead to