Image credits
Photos and illustrations on this site are either our own work or come from sources whose licence allows reuse. Each is credited below and again under the image where it appears. © 2026 forcsguy.com for original lessons and diagrams.
Logos and trademarks
Company and technology logos on this site come from Simple Icons (CC0 icon paths). They remain trademarks of their owners and appear only to name the product or technology being discussed. None of them implies sponsorship, partnership or endorsement. Amazon has no openly licensed mark, so it is shown with a parcel icon drawn for this site.
Photos and illustrations

Wikimedia Commons: Lajes Field Air Traffic Control
By Senior Airman John Wright · Public domain · Source

Wikimedia Commons: Ford assembly line - 1913
By Unknown authorUnknown author · Public domain · Source

Wikimedia Commons: NIST-F2 cesium fountain atomic clock
By National Institute of Standards and Technology (NIST) · Public domain · Source

Wikimedia Commons: Bank vault 1901
By P199 · Public domain · Source

Wikimedia Commons: Wooden Card Catalog Furniture
By MarkBuckawicki · CC0 · Source

Wikimedia Commons: Circuit breaker, Single pole, Non-tripfree, 20Amp-30Volts, AN 3160 pic1
By Alf van Beem · CC0 · Source

Wikimedia Commons: Peabird Ethernet switch in 2003
By Syced · CC0 · Source

Wikimedia Commons: Hard disk drive platter, Samsung MP0402H
By Mk2010 · CC BY 4.0 · Source

Wikimedia Commons: Western Digital SN850X NVME solid state drive 8TB front side
By 4300streetcar · CC BY 4.0 · Source

Wikimedia Commons: Fujikura optic fiber at Science Museum
By Syced · CC0 · Source

Wikimedia Commons: Three padlocks
By Mx. Granger · CC0 · Source

Wikimedia Commons: LaCuCa card reader - payment terminal at supermarket register
By Syced · CC0 · Source

Wikimedia Commons: RZD Selizarovo 2016-08 searchlight signal 2
By Svetlov Artem · CC0 · Source

Wikimedia Commons: Dual-channel DDR memory use 6026
By Mixabest · Public domain · Source

Wikimedia Commons: Technician with laptop working on server rack at NERSC
By Derrick Coetzee · CC0 · Source

Wikimedia Commons: Smartphone Use
By Océanos y dados · CC0 · Source

Wikimedia Commons: Residential smoke detector
By Oleg Alexandrov · Public domain · Source

Wikimedia Commons: Old Post Sorting Office, Portsmouth
By Tim Sheerman-Chase · CC BY 2.0 · Source

Wikimedia Commons: Transatlantic submarine cable map
By Howe's Adventures & Achievements of Americans · Public domain · Source

Wikimedia Commons: Columbia Supercomputer - NASA Advanced Supercomputing Facility
By Trower, NASA · Public domain · Source

Wikimedia Commons: Magnetic tape library at USDA
By U.S. Department of Agriculture · Public domain · Source

Wikimedia Commons: Telephone switchboard 6 Oct 1907 Salt Lake City
By The Salt Lake Herald · Public domain · Source

Wikimedia Commons: Peaje - Toll - Péage (5020183265)
By Spanish Coches · CC BY 2.0 · Source

Wikimedia Commons: NY stock exchange traders floor LC-U9-10548-6
By Thomas J. O'Halloran · Public domain · Source

Wikimedia Commons: Gulf, traffic jam 1970s
By Digitura · CC0 · Source

Wikimedia Commons: People waiting in line at Stena Line ferry terminal, Frederikshavn
By W.carter · CC0 · Source

Wikimedia Commons: FEMA - 37526 - Florida Logisitics Response center
By Barry Bahler · Public domain · Source