Communication

Semantics: the study of meaning in language, signs, and symbols Semantics An overview of semantics: core concepts, history, major subfields, examples of ambiguity and compositionality, and how semantics connects to linguistics, philosophy, logic and comp…

Semaphore line (optical telegraph) Semaphore line A semaphore line is a system for sending visual signals across distances using towers, movable arms, shutters or hand-held flags—precursor to electrical telegraphy and still used i…

Semicolon: punctuation mark and its uses Semicolon Overview of the semicolon ; — its grammatical roles, typographic form, history, examples, and use in programming, with common pitfalls and style guidance.

Semiotics: The study of signs, symbols, and meaning Semiotics Semiotics is the interdisciplinary study of signs and sign-systems—how meaning is produced, organized and interpreted across language, images, gestures, objects, and sensory signal…

Semiotics of Culture Study of culture as a system of signs and meanings: its structures, processes of semiosis, history in the Tartu–Moscow school, and applications to texts, rituals, and media.

Semivowel (phonetics) Semivowel Semivowels (also called glides) are consonant sounds that are vowel-like in quality; this article explains their articulation, notation, history in writing systems, and roles acros…

Sensitive information: definition, types, protection, and risks Sensitive information An overview of sensitive information: what it is, common types, why it matters, how it is classified and protected, and the harms that can result from unauthorized disclosure.

Sensorineural Hearing Loss: Causes, Features, Diagnosis, and Management Sensorineural An overview of sensorineural hearing loss (nerve deafness): what it is, how it differs from conductive loss, common causes, symptoms, diagnosis, treatment options and important dis…

Sentence (linguistics): definition, structure, types and uses Sentence A sentence is a coherent string of words that conveys a complete thought. This article explains its components, types, grammatical formation, historical perspectives, and everyday…

Serbian: language, people and culture Serbian Overview of Serbian as an adjective and noun: the South Slavic language, its writing systems and dialects, the Serb people, cultural traits, history, and contemporary usage.

Serbian Cyrillic alphabet The Serbian Cyrillic alphabet is a 30‑letter phonemic script standardized in the 19th century and used for the Serbian language alongside a Latin alphabet. It is known for its one‑…

Serbian language A South Slavic language spoken mainly by Serbs in the Balkans and worldwide; notable for its dual scripts, dialect diversity, and 19th-century standardization by Vuk Karadžić.

Serbo-Croatian (South Slavic language) Serbo-Croatian Serbo-Croatian is a South Slavic lect historically used across the Western Balkans; it underlies the modern Croatian, Serbian, Bosnian and Montenegrin standard varieties and remain…

Sercquiais (Sarkese) — the Norman dialect of Sark Sercquiais Sercquiais, or Sarkese, is a highly endangered Norman language variety from the Channel Island of Sark. It descends from Jèrriais and survives today only among a handful of speaker…

Serial communication: principles, types, and practical uses Serial communication Overview of serial communication: how it transmits bits sequentially, common protocols and interfaces, historical development, advantages vs parallel links, and typical application…

Sha (Ш, ш) — Cyrillic letter for the /ʃ/ sound Sha (Cyrillic) Sha (Ш, ш) is a Cyrillic consonant representing the voiceless postalveolar fricative /ʃ/. Covers origin, forms, pronunciation, transliteration and use across Slavic and non‑Slavic…

Shahmukhi — the Perso‑Arabic script for Punjabi Shahmukhi Shahmukhi is the Perso‑Arabic script used to write Punjabi in Pakistan. It is written right-to-left, functions as an abjad with added letters for Punjabi sounds, and is used in lit…

Shin (Hebrew letter) Shin (letter) Shin is the twenty-first letter of the Hebrew alphabet, representing /ʃ/ or /s/ depending on a diacritic. It has historical roots in Proto‑Semitic sibilants and symbolic uses in Ju…

Ship's bell (maritime timekeeper and ceremonial bell) Ship's bell A ship's bell is a heavy bronze or brass bell carried aboard vessels for timekeeping, signalling, ceremonies and identification. It has naval, cultural, and practical roles on merc…

Shipping Forecast The Shipping Forecast is a regular maritime weather bulletin for the seas around the British Isles, produced by the Met Office for the Maritime and Coastguard Agency and broadcast…

Shit — slang term for feces and common English profanity Shit A neutral overview of the word “shit”: its meanings as a term for feces, grammatical uses, history, cultural attitudes, related words, and issues of censorship and etiquette.

Sho (Greek-derived letter used for the Bactrian 'sh') Sho (letter) Sho (Ϸ ϸ) is a letter added to the Greek alphabet to write Bactrian, representing the /ʃ/ sound. It appears in inscriptions and coins and is encoded in the Greek Extended Unicode b…

Short circuit (electrical fault): causes, effects and prevention Short circuit A short circuit is an unintended low-resistance path that allows excessive current to flow. This article explains causes, types, effects, detection, protection and safe work practi…

Short I (Cyrillic letter Й) Short I Short I (Й, й) is a Cyrillic letter formed from И with a breve. It usually represents the palatal approximant /j/ (the 'y' sound) in several Slavic and related alphabets and is tre…

Shorthand (Stenography): systems, history, and modern uses Shorthand Shorthand, or stenography, is a rapid writing method using symbols or abbreviations. This article explains techniques, major systems, historical development, and contemporary appli…

High-Frequency (Shortwave) Radio: International Broadcasting, Propagation, and Uses Shortwave radio Overview of high-frequency (shortwave) radio: spectrum, ionospheric propagation, solar effects, and its uses in international broadcasting, time/weather services, commercial, relig…

Siberian languages Siberian languages is a broad label for the many languages spoken across Siberia, including Russian and numerous Indigenous language families.

Sicel language (Sikel): overview of an ancient Sicilian tongue Sicel language Ancient Indo-European language spoken by the Sicels of Sicily. Known from a small corpus of inscriptions, names and place-names; its precise classification is uncertain but shows I…

Sicilian language (Lu sicilianu) Sicilian language A concise overview of the Sicilian language: features, history, regional use in Sicily and Calabria, influences, varieties, and cultural significance.

Sign (indicator, signal, symbol) Sign A sign is anything perceived that conveys meaning—natural or created—ranging from seasonal cues and medical measurements to traffic signals, symbols, and forms of communication lik…

Sign language Visual-manual languages used primarily by Deaf communities. Natural languages with their own grammar, history, varieties, and social roles, distinct from body language and spoken l…

Signal (communication, control and biological signalling) Signal A signal is any observable or measurable event used to convey information, coordinate action, or trigger responses across physical, biological, social, or engineered systems.

Biological signal: communication within and between living systems Signal (biology) A biological signal is any coded message used by cells, tissues or organisms to convey information—electrical, chemical, mechanical or behavioral—supporting coordination, response…

Signal (electrical engineering) A signal is a time-varying physical quantity that conveys information. This article explains types, representations, history, analysis tools, applications, and key distinctions in…

Signal processing: principles, methods, and applications Signal processing Overview of signal processing: key concepts, common techniques, historical development, and major applications across audio, image, communications and biomedical fields.

Signature (handwritten, stamped, and electronic marks of identity and consent) Signature A signature is a person's distinctive mark or written name used to indicate identity, approval, authorship or intent; forms include handwritten signatures, seals and modern electro…

Sikkimese (Dranjongke): Tibetic language of Sikkim's Bhutia community Sikkimese language Overview of Sikkimese (Dranjongke), a Tibetic language of the Bhutia people in Sikkim and nearby Nepal: classification, Tibetan script, dialects, registers, usage and cultural sign…

Silence: absence of sound, cultural practice, and legal concept Silence An overview of silence as the absence of audible sound, its forms and uses in culture, law and health, and practical distinctions between physical, social and reflective silence.

Silent letter Silent letters are written characters that are not pronounced. This article explains their origins, functions in spelling, common English examples, cross‑linguistic patterns, and i…

Silesian language: overview, features, history and contemporary use Silesian language Silesian (Upper Silesian) is a West Slavic lect spoken mainly in Silesia. Its classification as a separate language or a Polish dialect is debated; it has distinct phonology, vocab…

Simlish: The Fictional Language of The Sims Simlish Simlish is the playful, nonstandard vocalization used by characters in The Sims franchise. Created for expressive, nonlocalized speech, it appears across Sims games and in pop-cult…

Simple English: forms, purposes, and controlled-language systems Simple English An overview of Simple English — controlled and plain-language forms used in education, broadcasting, technical writing and online resources, including key standards and examples.

Simple Mail Transfer Protocol (SMTP) Simple Mail Transfer Protocol SMTP is the Internet standard protocol for sending and relaying email between servers. It defines client-server commands, extensions like STARTTLS and AUTH, and works with delivery…

Simple sentence A simple sentence is an independent clause that contains a subject and predicate, expresses a complete thought, and stands alone as a grammatically complete unit.

Simplified Chinese characters An overview of Simplified Chinese characters: their form, development, regional use, benefits and limits, and how they compare to traditional characters.

Simplified Technical English (Simplified English) Simplified English A controlled form of English for technical documentation that uses a restricted vocabulary and writing rules to reduce ambiguity, improve readability for non-native speakers, and a…

Sindhi language Sindhi is an Indo-Aryan language of the Sindh region, spoken mainly in Pakistan and India; it has several writing systems, a long literary tradition, and distinctive phonetic featu…

Singlish: the English-based colloquial speech of Singapore Singlish Singlish is an English-derived colloquial variety widely used in Singapore, blending elements from Malay, Chinese dialects, Tamil and other languages and serving as a marker of loc…