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Computing Fundamentals
Computing fundamentals covers the foundational concepts underlying all computer systems: binary representation, logic gates, processor operation, memory, storage, operating systems, and networking. It provides the mental model for understanding how software instructions become physical actions.
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Intro
Computing Fundamentals
A computer turns instructions and data into useful results. That compact idea connects every laptop, phone, server, and embedded device. The scale and packaging change. The basic system remains a combination of hardware, software, data, and communication.
You do not need to memorize every component. You need a mental model that helps you place a problem in the right layer.
The working model
Think of a computer as five cooperating parts:
- Input brings data and instructions into the system.
- Processing executes instructions and transforms data.
- Memory holds instructions and data needed now.
- Storage retains programs and data for later use.
- Output and networking deliver results to people, devices, or other computers.
Hardware provides the physical resources. Software supplies instructions. The operating system coordinates the two and gives applications common services.
Hardware: the physical machine
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Sources
- https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-223.pdf
Supports
- Computers include CPUs, memory, disk space, and network interfaces
- A software stack includes an operating system, compilers, and libraries
- Workload requirements determine relevant storage and network constraints
- https://csrc.nist.gov/glossary/term/byte
Supports
- A byte is a sequence of eight bits
- Byte values can be treated as integers from zero through 255
- https://csrc.nist.gov/glossary/term/os
Supports
- An operating system manages hardware resources and provides common program services
- Operating-system functions include scheduling, input and output, and data management
- Applications use the operating system for interface and file-management operations
- https://csrc.nist.gov/pubs/ir/7298/r3/final
Supports
- Standard terminology for security, authentication, authorization, and system concepts
- The need to interpret technical terms in their defined source context
- https://csrc.nist.gov/glossary/term/backup
Supports
- A backup is a copy of files and programs made to support recovery
- Backup has a recovery purpose distinct from active working data
- https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap01.html
Supports
- POSIX defines a standard operating-system interface and environment
- The environment includes a command interpreter and common utilities
- https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap03.html
Supports
- Formal definitions of file system, pathname, parent directory, and file permissions
- Process and parent-process terminology
- A pathname identifies a file
- https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap04.html
Supports
- Files are organized through a hierarchy containing directories
- Absolute and relative pathnames use different starting locations
- File-system access can pass through a memory cache
- https://pubs.opengroup.org/onlinepubs/9799919799/utilities/V3_chap02.html
Supports
- A shell is a command language interpreter
- A shell reads, tokenizes, parses, and executes commands
- https://pubs.opengroup.org/onlinepubs/9799919799/functions/fork.html
Supports
- A process has an identifier and can create a child process
- A new process receives defined process state and resource references
- https://www.rfc-editor.org/info/rfc1122/
Supports
- Internet communication uses application, transport, Internet, and link layers
- Hosts implement layered protocols for interoperability
- Network layers provide distinct responsibilities useful for fault isolation
- https://www.rfc-editor.org/rfc/rfc9293.html
Supports
- TCP provides reliable, ordered byte-stream service
- TCP carries byte streams in segments inside IP datagrams
- Sequence numbers, checksums, and retransmission contribute to reliability
- Ports identify application services and multiplex flows
- https://www.rfc-editor.org/info/rfc1035/
Supports
- DNS provides name-server access over Internet transports
- DNS queries and responses can be carried with UDP or TCP
- Name resolution is distinct from packet routing and application execution
- https://www.cisa.gov/secure-our-world
Supports
- Recognize and report phishing
- Use strong passwords and a password manager
- Turn on multifactor authentication
- Install software updates promptly
- https://support.apple.com/en-ae/guide/platform-support/supc3f7e97bc/web
Supports
- Systematic troubleshooting narrows symptoms across hardware, operating-system, connectivity, application, and service layers
- Isolation tests help distinguish possible root causes
- Lower-effort observations and tests should precede disruptive changes
- https://www.cisa.gov/resources-tools/training/how-protect-data-stored-your-devices
Supports
- Backup copies reduce the risk of permanent data loss
- Connected backup media can be deleted or corrupted by ransomware
- Backup and restoration guidance applies across major operating systems
- https://openstax.org/books/introduction-computer-science/pages/1-1-computer-science
Supports
- A broad computer-hardware model of processor, memory, network, and storage
- Software provides algorithms and instructions that operate on data
- Computing has technical limits related to computability and required resources
- https://openstax.org/books/introduction-computer-science/pages/5-1-computer-systems-organization
Supports
- Programs move from storage into memory for execution
- The CPU fetches, decodes, and executes instructions
- Registers, cache, memory, storage, buses, and input-output devices have distinct roles
- https://openstax.org/books/introduction-computer-science/pages/6-2-fundamental-os-concepts
Supports
- Applications request operating-system services through interfaces
- Operating systems manage processes, memory, files, devices, and input-output
- Device drivers expose hardware functions through software interfaces
- https://developer.mozilla.org/en-US/docs/Learn_web_development/Howto/Web_mechanics/How_does_the_Internet_work
Supports
- Switches connect devices on local networks
- Routers forward messages between networks
- Domain names provide human-readable names associated with network destinations
- The Web is a service built on Internet infrastructure
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/MIME_types
Supports
- A media type indicates the nature and format of bytes
- A file-name suffix can suggest a type but is not guaranteed to be correct
- Content can be examined for format markers when explicit type information is absent
- https://www.nand2tetris.org/
Supports
- The materials build a general-purpose computer and software hierarchy from first principles
- The course provides lectures, projects, and tools for practical progression
- https://ocw.mit.edu/courses/6-033-computer-system-engineering-spring-2018/
Supports
- Advanced study includes modularity, client-server design, operating systems, performance, and networks
- The course also covers naming, security, privacy, fault tolerance, and recovery