INTRODUCTION TO COMPUTER SYSTEM

• A computer system is defined as a combination of hardware components, such as a processing unit, memory, input/output devices, and storage, along with software components like operating systems and applications, working together to achieve a specific purpose in the field of Computer Science.
• A computer system primarily comprises a central processing unit (CPU), memory, input/output devices and storage devices.
• Just like how our brain controls our body and processes information, the CPU carries out instructions from programs and performs calculations.

COMPONENTS OF COMPUTER SYSTEM

CPU (CENTRAL PROCESSING UNIT)

•  A CPU is hardware that performs data input/output, processing, and storage functions for a computer system. 
•  It is the brain of the computer.  Just like how our brain controls our body and processes information, the CPU carries out instructions from programs and performs calculations. 
• All types of data processing operations from simple arithmetic to complex tasks and all the important functions of a computer are performed by the CPU.

• CPU consists of 3 major units, which are:

  • Memory or Storage Unit
  • Control Unit
  • ALU(Arithmetic Logic Unit)

MEMORY OR STORAGE UNIT

• The memory unit is responsible for transferring information to other units of the computer when needed.
•  It is also known as an internal storage unit or the main memory or the primary storage or Random Access Memory (RAM) as all these are storage devices.

CONTROL UNIT

•  A control unit controls the operations of all parts of the computer but it does not carry out any data processing operations. 
• Executing already stored instructions, It instructs the computer by using the electrical signals to instruct the computer system.
• It takes instructions from the memory unit and then decodes the instructions after that it executes those instructions.
• Its main task is to maintain the flow of information across the processor.

ALU (ARITHMETIC LOGIC UNIT)

• ALU (Arithmetic Logic Unit) is responsible for performing arithmetic and logical functions or operations.

• It consists of two subsections, which are:

  • Arithmetic Section: By arithmetic operations, we mean operations like addition, subtraction, multiplication, and division, and all these operations and functions are performed by ALU. Also, all the complex operations are done by making repetitive use of the mentioned operations by ALU.
  • Logic Section: By Logical operations, we mean operations or functions like selecting, comparing, matching, and merging the data, and all these are performed by ALU.

COMPUTER HARDWARE

• Computer hardware includes the physical parts of a computer, such as a case, central processing unit (CPU), random access memory (RAM), monitor, and mouse which processes the input according to the set of instructions provided to it by the user and gives the desired output.

• These hardware components are further divided into the following categories, which are:

  1. Input Devices
  2. Output Devices
  3. Storage Devices
  4. Internal Components

COMPUTER SOFTWARE

• Computer Software serves as the backbone of all digital devices and systems. It is an integral part of modern technology.
• Unlike hardware which comprises physical components, software is intangible and exists as a code written in programming language.

TYPES OF COMPUTER SOFTWARE

SYSTEM SOFTWARE

• System software manages hardware and basic system operations and serves as a foundation for application software. It serves as a bridge between hardware and use r and ensures that the system operates efficiently and effectively.
• This includes Operating Systems, Device Drivers, and Utility Software.

APPLICATION SOFTWARE

• Application Software refers to the programs designed to perform specific tasks for end-users such as web browsing, gaming, word processing, etc.
•  This includes Productivity Software (Microsoft Office, Google Workspace), Database Software (MySQL, Oracle Database), Communication Software (Slack, Skype), and Graphics Software (Adobe Photoshop, CoralDraw).

DEVELOPMENT SOFTWARE

• Development Software includes tools and environments that are used by developers and programmers to create, debug, and maintain software applications. 
• This includes IntegerateDevelopmentnt Environments (Eclipse, Microsoft Visual Studio), Code Editors (Atom, Visual Studio Code), and Version Control Software (Git, GitHub).

BUSINESS SOFTWARE

• Business Software refers to the applications that assist organizations in managing their operations, improving productivity, and facilitating various business activities. 
• This includes Enterprise Resource Planning (ERP), Customer Relationship Management (CRM), and Accounting Software (QuickBooks, Xero).

EMBEDDED SOFTWARE

• Embedded software is computer software that is designed to operate hardware and perform specific tasks within a larger system. It is optimized for particular functions and integrated into the hardware it controls. 
• This includes Firmware (BIOS in computer) and Control Systems (Software in automotive control systems).

HARDWARE VS SOFTWARE

GENERATIONS OF COMPUTER:

First Generation Computers: Vacuum Tubes (1940-1956)

• The technology behind the primary generation computers was a fragile glass device, which was called vacuum tubes.
• These computers were very heavy and really large in size.
• These weren’t very reliable and programming on them was a tedious task as they used low-level programming language and used no OS.
• They were too bulky and large that they needed a full room and consume a lot of electricity. Punch cards were used for improving the information for external storage.
• Examples of some main first-generation computers are :
• ENIAC: Electronic Numerical Integrator and Computer, built by J. Presper Eckert and John V. Mauchly was a general-purpose computer. It had been cumbersome, and large, and contained 18,000 vacuum tubes.
• EDVAC: Electronic Discrete Variable Automatic Computer was designed by von Neumann. It could store data also as instruction and thus the speed was enhanced.
• UNIVAC: Universal Automatic Computer was developed in 1952 by Eckert and Mauchly.

Second Generation Computers: Transistors (1956-1963)

• Second-generation computers used the technology of transistors rather than bulky vacuum tubes.
• A transistor may be a device composed of semiconductor material that amplifies a sign or opens or closes a circuit.
• Transistors were invented in Bell Labs. The use of transistors made it possible to perform powerfully and with due speed. It reduced the dimensions and price and thankfully the warmth too, which was generated by vacuum tubes.

Third Generation Computers: Integrated Circuits (1964-1971)

• During the third generation, technology envisaged a shift from huge transistors to integrated circuits, also referred to as IC.
• The most feature of this era’s computer was speed and reliability.
• “Integrated Circuits” it was developed in 1958 by “Jack Kilby”.

Fourth Generation Computers: Micro-processors (1971-1990)

• In 1971 First microprocessors were used, the large-scale of integration LSI circuits built on one chip called microprocessors.
• The advantage of this technology is that one microprocessor can contain all the circuits required to perform arithmetic, logic, and control functions on one chip. LSI placed thousands of transistors onto a single chip.
• This generation provided even smaller size of computers, with larger capacities. That’s not enough, then Very Large Scale Integrated (VLSI) circuits replaced LSI circuits. 

Fifth Generation Computers: (Present- future)

• The technology behind the fifth generation of computers is AI.
• It allows computers to behave like humans. It is often seen in programs like voice recognition, area of medicine, and entertainment.
• The speed is the highest, size is the smallest and area of use has remarkably increased within the fifth generation computers.
• Though not a hundred percent AI has been achieved to date but keeping in sight the present developments, it is often said that this dream also will become a reality very soon.