Introduction to Computer Systems

Introduction to Computer Systems

• A computer system comprises input, processing, memory, and output units.
• The central processing unit (CPU) includes the control unit and arithmetic logic unit (ALU).
• Registers store data temporarily.

A World of Information

• Computers are ubiquitous, present at workplaces, schools, and homes.
• Mobile computers and devices are compact and portable.
• Mobile devices, often classified as computers, are a major communication tool globally.
• Computers provide instant access to information worldwide.
• ATMs (automated teller machines) are embedded computers enabling financial transactions anytime, anywhere.
• Vehicles commonly have onboard navigation systems (embedded computers) offering directions, emergency services, and theft tracking.
• People use computers for recreational activities like gaming, listening to music, and watching broadcasts.

What Is a Computer?

• A computer is an electronic device that operates under the control of instructions stored in its own memory.
• Computers accept data, process data according to rules, produce results, and store results.

Data and Information

• Computers process data into information.
• Data is a collection of unprocessed items (text, numbers, images, audio, video).
• Information conveys meaning and is useful for people.
• Computers transform data items into printed information like cash register receipts.

Information Processing Cycle

• Computers process data (input) into information (output).
• Instructions are steps that tell the computer what to do.
• Software is a collection of related instructions for a common purpose.
• The information processing cycle involves input, process, output, and storage processes.
• Communications have become essential to the information processing cycle.

The Components of a Computer

• Computers consist of numerous electronic and mechanical parts, known as hardware.
• Input devices accept data and instructions (keyboard, mouse, microphone, scanner, webcam).
• Output devices convey information to users (printer, monitor, speakers).
• The system unit contains the CPU (central processing unit) and memory.
• Storage devices hold data permanently (hard disks, optical discs, USB flash drives, memory cards).
• Communication devices connect computers (modem).

System Unit

• The system unit encloses the internal electronic components that process data.
• The motherboard is the key circuit board within that unit.
• The processor/CPU is the electronic component that interprets and executes instructions.
• Memory stores instructions and data needed for execution; it is volatile (contents lost when the power is off).

Storage Devices

• Storage permanently holds data, instructions, and information.
• Examples include hard disks, optical discs (like DVDs), flash drives, and memory cards.
• Storage devices record (write) and retrieve (read) data to and from storage media.

Communications Devices

• A communications device allows a computer to send and receive data, instructions, and information with other computers or devices.
• A modem is a common communication device.
• Communications occur over various transmission media (cables, phone lines, cellular networks, satellites).
• Some communications (such as via satellites or cellular networks) are wireless.

Computer Characteristics

• Speed: Data, instructions, and information move very rapidly along electronic circuits.
• Reliability: Modern electronic components seldom malfunction.
• Consistency: Input and processes usually produce consistent results.
• Storage: Data can be quickly transferred to and from memory for processing and then saved for future use.
• Communications: Computers can communicate with other computers wirelessly and share data.

Computers Misuse

• Prolonged or improper computer use can lead to health problems (carpal tunnel, eye strain, back pain).
• Preventing such problems involves suitable workspace design, good posture, and regular breaks.
• Computer overuse can lead to behavioral health problems like addiction and technology overload.

Violation of Privacy

• Computers store extensive data about individuals, including medical records and financial information.
• Privacy can be violated by unauthorized access and data theft.

Public Safety

• Individuals use computers to share images, videos, journals, and other personal information, sometimes without considering the potential risks of making this information publicly available.
• Public access to this data can have negative consequences for those individuals.

Networks and the Internet

• A network connects computers and devices.
• Networks share resources (hardware, software, data) saving time and money.
• The server controls access to resources (data, programs) for the network clients/workstations.
• The Internet is the world's largest network.

The Internet

• The Internet connects millions of businesses, government agencies, educational institutions and individuals.
• People use the Internet for various activities.

The Web

• The Web is a widely used Internet service.
• Web pages are documents with built-in connections/links to other pages.
• A website is a collection of related web pages.
• A blog is a website containing timestamped articles.
• Web applications are software used via the internet.