Glossary - Hyper-Text Markup Language (HTML)

HTML, which is an acronym for Hyper-Text Markup Language, is the primary computer language used with the World Wide Web for the design and presentation of web pages.  Web browsers parse HTML code and present the information to the user accordingly.

As computer languages go, HTML is easy to learn because it is generally very simple in its structure with a fairly small command-set, which is one of the reasons it gained popularity so quickly in the 1990s when many non-technical people had started learning the basics of HTML syntax to create some simple web pages.  For an easy-to-read example of HTML syntax that also reveals structure in a simple manner, you can view the HTML source code of this web page (most web browsers include an HTML source code viewing option, typically in the "View" menu).

If you're interested in learning standards-compliant HTML, we recommend that you start with the Opera Web Standards Curriculum at http://www.opera.com/company/education/curriculum/ which is freely available to everyone.

HTML markers

The syntax of HTML is comprised mainly of markers (or HTML tags, or elements) and free-form text, and also entity references (special characters).  Elements, which essentially specify the formatting rules, are enclosed within less-than and greater-than signs, such as <p> (this starts a new paragraph of free-form text).

An extensive and very detailed list of HTML markers (and HTML document structure) is available in RFC 1866 -- see pages 11 and 12 for an example of a basic structure, and section 5, which begins on page 20, for the detailed reference list of HTML markers.

Entity references

Entity references, which provide a way to include special characters, are enclosed within an ampersand and a semi-colon, such as &amp; (this presents an ampersand, a well-known entity reference).

The first 255 entity references are documented throughout RFC 1866, with the majority listed on pages 72 through 75.  Other widely-supported entity references are included in the table below for your convenience...

Character Description Entity references ƒ Latin small f with hook; function; florin ƒ ƒ ƒ Α Greek capital letter alpha Α Α Α Β Greek capital letter beta Β Β Β Γ Greek capital letter gamma Γ Γ Γ Δ Greek capital letter delta Δ Δ Δ Ε Greek capital letter epsilon Ε Ε Ε Ζ Greek capital letter zeta Ζ Ζ Ζ Η Greek capital letter eta Η Η Η Θ Greek capital letter theta Θ Θ Θ Ι Greek capital letter iota Ι Ι Ι Κ Greek capital letter kappa Κ Κ Κ Λ Greek capital letter lambda Λ Λ Λ Μ Greek capital letter mu Μ Μ Μ Ν Greek capital letter nu Ν Ν Ν Ξ Greek capital letter xi Ξ Ξ Ξ Ο Greek capital letter omicron Ο Ο Ο Π Greek capital letter pi Π Π Π Ρ Greek capital letter rho Ρ Ρ Ρ Σ Greek capital letter sigma Σ Σ Σ Τ Greek capital letter tau Τ Τ Τ Υ Greek capital letter upsilon Υ Υ Υ Φ Greek capital letter phi Φ Φ Φ Χ Greek capital letter chi Χ Χ Χ Ψ Greek capital letter psi Ψ Ψ Ψ Ω Greek capital letter omega Ω Ω Ω α Greek small letter alpha α α α β Greek small letter beta β β β γ Greek small letter gamma γ γ γ δ Greek small letter delta δ δ δ ε Greek small letter epsilon ε ε ε ζ Greek small letter zeta ζ ζ ζ η Greek small letter eta η η η θ Greek small letter theta θ θ θ ι Greek small letter iota ι ι ι κ Greek small letter kappa κ κ κ λ Greek small letter lambda λ λ λ μ Greek small letter mu μ μ μ ν Greek small letter nu ν ν ν ξ Greek small letter xi ξ ξ ξ ο Greek small letter omicron ο ο ο π Greek small letter pi π π π ρ Greek small letter rho ρ ρ ρ ς Greek small letter final sigma ς ς ς σ Greek small letter sigma σ σ σ τ Greek small letter tau τ τ τ υ Greek small letter upsilon υ υ υ φ Greek small letter phi φ φ φ χ Greek small letter chi χ χ χ ψ Greek small letter psi ψ ψ ψ ω Greek small letter omega ω ω ω ϑ Greek small letter theta symbol ϑ ϑ ϑ ϒ Greek upsilon with hook symbol ϒ ϒ ϒ ϖ Greek pi symbol ϖ ϖ ϖ • bullet; black small circle • • • … horizontal ellipsis; three dot leader … … … ′ prime; minutes; feet ′ ′ ′ ″ double prime; seconds; inches ″ ″ ″ ‾ overline; spacing overscore ‾ ‾ ‾ ⁄ fraction slash ⁄ ⁄ ⁄ ℘ script capital P; power set; Weierstrass p ℘ ℘ ℘ ℑ blackletter capital I; imaginary part ℑ ℑ ℑ ℜ blackletter capital R; real part symbol ℜ ℜ ℜ ™ trade mark sign ™ ™ ™ Character Description Entity references

Character Description Entity references ℵ alef symbol; first transfinite cardinal ℵ ℵ ℵ ← leftwards arrow ← ← ← ↑ upwards arrow ↑ ↑ ↑ → rightwards arrow → → → ↓ downwards arrow ↓ ↓ ↓ ↔ left right arrow ↔ ↔ ↔ ↵ downwards arrow with corner leftwards; carriage return ↵ ↵ ↵ ⇐ leftwards double arrow ⇐ ⇐ ⇐ ⇑ upwards double arrow ⇑ ⇑ ⇑ ⇒ rightwards double arrow ⇒ ⇒ ⇒ ⇓ downwards double arrow ⇓ ⇓ ⇓ ⇔ left right double arrow ⇔ ⇔ ⇔ ∀ for all ∀ ∀ ∀ ∂ partial differential ∂ ∂ ∂ ∃ there exists ∃ ∃ ∃ ∅ empty set; null set; diameter ∅ ∅ ∅ ∇ nabla; backward difference ∇ ∇ ∇ ∈ element of ∈ ∈ ∈ ∉ not an element of ∉ ∉ ∉ ∋ contains as member ∋ ∋ ∋ ∏ n-ary product; product sign ∏ ∏ ∏ ∑ n-ary sumation ∑ ∑ ∑ − minus sign − − − ∗ asterisk operator ∗ ∗ ∗ √ square root; radical sign √ √ √ ∝ proportional to ∝ ∝ ∝ ∞ infinity ∞ ∞ ∞ ∠ angle ∠ ∠ ∠ ∧ logical and; wedge ∧ ∧ ∧ ∨ logical or; vee ∨ ∨ ∨ ∩ intersection; cap ∩ ∩ ∩ ∪ union; cup ∪ ∪ ∪ ∫ integral ∫ ∫ ∫ ∴ therefore ∴ ∴ ∴ ∼ tilde operator; varies with; similar to ∼ ∼ ∼ ≅ approximately equal to ≅ ≅ ≅ ≈ almost equal to; asymptotic to ≈ ≈ ≈ ≠ not equal to ≠ ≠ ≠ ≡ identical to ≡ ≡ ≡ ≤ less-than or equal to ≤ ≤ ≤ ≥ greater-than or equal to ≥ ≥ ≥ ⊂ subset of ⊂ ⊂ ⊂ ⊃ superset of ⊃ ⊃ ⊃ ⊄ not a subset of ⊄ ⊄ ⊄ ⊆ subset of or equal to ⊆ ⊆ ⊆ ⊇ superset of or equal to ⊇ ⊇ ⊇ ⊕ circled plus; direct sum ⊕ ⊕ ⊕ ⊗ circled times; vector product ⊗ ⊗ ⊗ ⊥ up tack; orthogonal to; perpendicular ⊥ ⊥ ⊥ ⋅ dot operator ⋅ ⋅ ⋅ ⌈ left ceiling; APL upstile ⌈ ⌈ ⌈ ⌉ right ceiling ⌉ ⌉ ⌉ ⌊ left floor; APL downstile ⌊ ⌊ ⌊ ⌋ right floor ⌋ ⌋ ⌋ ⟨ left-pointing angle bracket; bra ⟨ 〈 〈 ⟩ right-pointing angle bracket; ket ⟩ 〉 〉 ◊ lozenge ◊ ◊ ◊ ♠ black spade suit ♠ ♠ ♠ ♣ black club suit; shamrock ♣ ♣ ♣ ♥ black heart suit; valentine ♥ ♥ ♥ ♦ black diamond suit ♦ ♦ ♦ Character Description Entity references

Enhancements

JavaScript (JS) and Cascading Style Sheets (CSS) are two client-side technologies that are used to improve the functionality and presentation of internet web sites.  When combined with server-side programming, web sites can become truly dynamic in nature, such as with Google's search results that appear before the user presses the [Enter] key or uses the Search button.

A wide range of plug-in technologies have also been developed that further enhance the web browsing experience.  In particular, technologies such as Java, Flash, Shockwave, PDF Reader, VLC Player, and QuickTime Player are among the most popular free plug-ins due to the popularity among web developers looking for ways to improve the overall end-user experience.  Of course, HTML provides the foundation that makes it possible to seamlessly combine all these technologies with relative consistency across many different environments.

See also

• File Transfer Protocol (FTP)
• HTML (extensive definition by Roedy Green)
• Opera Web Standards Curriculum
• RFC 1866 - Hypertext Markup Language - 2.0
• RFC 2854 - The "text/html" Media Type
• Web browsers

Copyright © Inter-Corporate Computer & Network Services, Inc.  All rights reserved.
All trademarks are the property of their respective owners.