CD

Cd,

symbol for the element cadmiumcadmium
[from cadmia, Lat. for calamine, with which cadmium is found associated], metallic chemical element; symbol Cd; at. no. 48; at. wt. 112.411; m.p. 321&degC;; b.p. 765&degC;; sp. gr. 8.65 at 20&degC;; valence +2.
..... Click the link for more information. .

CD:

see compact disccompact disc
(CD), a small plastic disc used for the storage of digital data. As originally developed for audio systems, the sound signal is sampled at a rate of 44,100 times a second, then each sample is measured and digitally encoded on the 4 3-4 in (12 cm) disc as a series of
..... Click the link for more information. .

CD

Abbrev. for Córdoba Durchmusterung. See Bonner Durchmusterung.

Cd

(chemistry) cadmium

CD

(optics) circular dichroism

candela

The International Standard unit of luminous intensity; closely approximates the formerly accepted unit known as the “international candle.”

CD

(1)Compact Disc

cd

(operating system)change directory.

cd

(networking)The country code for the Democratic Republicof the Congo (formerly Zaire, zr).

CD

(1) See carrier detect, candela and continuous delivery.

(2) (Change Directory) A command in DOS/Windows that changes the current command line directory (see Chdir). CD also does the same thing in Unix/Linux (see Unix commands).

(3) (Compact Disc) An optical digital audio disc that contains up to 74 minutes of hi-fi stereo sound. Introduced in the U.S. in 1983, the disc is a plastic platter (120mm/4.75" diameter) recorded on one side, with individual tracks playable in any sequence. Its storage capacity is from 650MB to 700MB. Other forms of CDs, such as CD-ROM, CD-I and Video CD, all stem from the original Compact Disc-Digital Audio (CD-DA) format. CDs can be played in CD, CD-ROM, CD-R, CD-RW and most DVD drives. For more on how CDs are made, see CD-ROM.

Sound is converted into digital code by sampling the sound waves 44,056 times per second and converting each sample into a 16-bit number. CDs use 1.411 million bits for each second of stereo sound, although this bandwidth requirement is reduced considerably when music compression formats are used (see MP3 and AAC). The tracks are recorded as microscopic pits in a groove that starts at the center of the disc and spirals outward to the edge.

A Note on Terminology
In the early 1990s when CD-ROMs first became popular, "CD" meant music, and "CD-ROM" meant data. Today, "CD" refers to both audio CDs and data CD-ROMs, which also include CD-R and CD-RW media. See CD-ROM and mini CD.

The Books
Documentation for various CD formats are found in books commonly known by the color of their covers.

 Red Book - CD-DA (Audio) Yellow Book - CD-ROM (Data) Orange Book - CD-R, CD-RW, Photo CD (Recordable) White Book - VCD (Video) Blue Book - CD Extra (Audio and data) Green Book - CD-I (Interactive)

What Happened to the Phonograph?

The audio CD was introduced in the U.S. in 1983, and within five years, CDs and CD players exceeded the sales of LPs and turntables.

From Carved Sound to Pits
Unlike phonograph records, in which the platter is literally carved with sound waves, CDs are recorded as microscopic pits covered by a clear, protective plastic layer. Instead of a needle vibrating in a groove, a laser shines onto the pits, and the reflections are decoded. Audio CDs, as well as all variations of the CD (CD-ROM, CD-R, etc.) use a spiral recording track like a phonograph record, but start at the center, not the edge. See analog audio.

Better Dynamic Range
Digital sound is cleaner than phonograph records because the numbers are turned into sound electronically. There are no needle pops and clicks and no tape hiss if the original recording was digital. In addition, the CD can handle a wider range of volume. A soft whisper can be interrupted by a loud cannon blast. If a phonograph record were recorded with that much "dynamic range," the needle would literally jump out of the groove.

Too Harsh for Critical Ears?
Pops and clicks aside, from the onset of audio CDs, many critics claimed digital sound was harsh and not as musical as the vinyl platter. DVD-Audio and SACD, two advanced digital formats with superior sound quality, came out in 1999, but neither one became popular (see DVD-Audio and SACD). See high-resolution audio.

In the meantime, turntables and vinyl records are still manufactured, although in smaller quantities, and this legacy industry is expected to persist. See turntable, laser turntable and USB turntable.

CD

Acronym	Definition
CD➣Compact Disc
CD➣Certificate of Deposit
CD➣Civil Defense
CD➣Candela (luminous intensity)
CD➣Change Directory (MS-DOS)
CD➣Current Directory
CD➣Color Display
CD➣Control Data
CD➣Community Development
CD➣Corporate Design
CD➣Calendar Day
CD➣Creative Director
CD➣Career Development
CD➣Committee Draft
CD➣Car and Driver (magazine)
CD➣Canadian Dollar
CD➣Candle
CD➣Cord
CD➣Council District
CD➣Cross Dresser
CD➣Conservation District
CD➣Concept Design
CD➣Comprehensive Database
CD➣Claude Debussy (classical composer)
CD➣Chad
CD➣Communication Device
CD➣Concept Development
CD➣Capacity Development (international economics)
CD➣Critical Decision
CD➣Curriculum Development
CD➣Celine Dion (Canadian singer)
CD➣Ciudad (city; postcode use, Mexico)
CD➣Center Director
CD➣Carrier Detect
CD➣Currently Disabled
CD➣Conduct Disorder
CD➣Companion Dog (AKC Obedience Title)
CD➣Content Dictionary
CD➣Chicken Dance
CD➣Collision Detection
CD➣Cordoba (Argentina province, airline code)
CD➣Collateral Damage
CD➣Club Deportivo
CD➣Christian Dior
CD➣Crossdresser (transvestite, drag)
CD➣College Dictionary
CD➣Congressional District
CD➣Conference on Disarmament
CD➣Cadmium
CD➣Contract Data
CD➣Critical Dimension
CD➣California Dreamin'
CD➣Cultural Development
CD➣Carpe Diem (MMORPG game)
CD➣Corporate Development
CD➣Continuous Delivery (software development)
CD➣Chemical Dependency
CD➣Country Director (Peace Corps)
CD➣Conceptual Design
CD➣Change of Direction
CD➣Call Data
CD➣Common Denominator
CD➣Contrary to the Discipline (Quaker religion)
CD➣Cold Drink
CD➣Component Design
CD➣Communications Director
CD➣Crohn's Disease
CD➣Creative Differences
CD➣Civil Defence
CD➣Civil Disobedience
CD➣Critical Design
CD➣Democratic Republic of the Congo (country code, top level domain)
CD➣Counter/Drug
CD➣Current Density
CD➣Center Distance
CD➣Control and Display
CD➣Celiac Disease
CD➣Communicable Disease
CD➣Consent Decree
CD➣Cold Drawn
CD➣Camp Director
CD➣Coastal Defense
CD➣Conserved Domain (proteins)
CD➣Cost Distribution
CD➣Cooldown
CD➣Cooldown (World of Warcraft gaming)
CD➣Capability Data (ITU-T)
CD➣Castle Douglas (Scotland, UK)
CD➣Cooperation and Development
CD➣Circular Dichroism
CD➣Controlled Drug
CD➣Clostridium Difficile
CD➣Clearance Delivery (aviation)
CD➣Context-Dependent (research parameter)
CD➣Chinese Dragon (automobile)
CD➣Cloaking Device (Star Trek)
CD➣Cortical Dysplasia (congenital abnormality)
CD➣Cruise Director
CD➣Combined Data
CD➣Cognitive Disabilities
CD➣Coeliac Disease
CD➣Counter-Drug
CD➣Canada Dry
CD➣Coefficient of Drag (aerodynamics)
CD➣Common Dialog (windows programming)
CD➣Carried Down
CD➣Cluster of Differentiation (aka Cluster of Designation; antigens)
CD➣Cytoplasmic Domain (immunology)
CD➣Central Division
CD➣Call Detail
CD➣Cloth-Diapering
CD➣Chromatic Dispersion
CD➣Capacitor Discharge (steel stud welding method)
CD➣Chronic Diarrhea
CD➣Computer Division (various locations)
CD➣Cavalry Division
CD➣Core Damage (nuclear reactors)
CD➣Contract Design
CD➣Chemical Defense
CD➣Circuit Description (Bell System)
CD➣Circuit Description
CD➣Corps Diplomatique
CD➣Climate Dynamics
CD➣Construction Defect
CD➣Comisión Directiva (Spanish)
CD➣Confidential Document
CD➣Climatological Data
CD➣Conservation Dependent (IUCN Red List of Threatened Species Lower Risk sub-category)
CD➣Common Drain (amplifier topology)
CD➣Cushing's Disease
CD➣Carnitine Deficiency
CD➣Chunichi Dragons (Japanese professional baseball team)
CD➣Cultural Diffusion
CD➣Cotrel-Dubousset (orthopedics)
CD➣Cash Dispenser
CD➣Consumers Digest
CD➣Cable Duct
CD➣Cash Disbursements (bookkeeping)
CD➣Cross Direction
CD➣Credit Derivative
CD➣Criteria Documents (NIOSH)
CD➣Conceptual Diagram
CD➣Conditional Discharge
CD➣Call Distributor (PBX feature)
CD➣Construction Document
CD➣Curriculum Director
CD➣Conseil de Discipline (French: Disciplinary Board)
CD➣Communication Disorder
CD➣Compliance Division
CD➣Community of Democracies
CD➣Chris Daniels (and the Kings; band)
CD➣Cuerpo Diplomático (Spanish)
CD➣Cuerpo Diplomático
CD➣Canine Distemper
CD➣Concept Definition
CD➣Common Digitizer (radar equipment)
CD➣Certificate of Destruction
CD➣Certified Doula
CD➣Cross Docking (shipping/inventory management)
CD➣Cross Docking (inventory management)
CD➣Cell Delay (ATM)
CD➣Compact Display
CD➣Correlation Dimension
CD➣Call Deflection
CD➣Cross Drive (tank transmission)
CD➣Converter Display
CD➣Country Direct
CD➣Consistency Determination
CD➣Cel Damage (video game)
CD➣Combat Development
CD➣Converter Drive
CD➣Ceské Dráhy (Czech railways)
CD➣Conference du Desarmement
CD➣Committee on Disarmament
CD➣Chart Datum
CD➣Control Drawing
CD➣Cordoba Durchmusterung (star catalogue)
CD➣Computational Device
CD➣Cultural Division
CD➣Complete Denture
CD➣Coil Driver
CD➣Call Disconnect
CD➣Cystitis Diet (veterinary prescription diet food)
CD➣Concurrent Disorders
CD➣Canadian Forces Decoration (medal)
CD➣Concrete Detail (writing)
CD➣Certification Division (EPA)
CD➣Calibration Drift
CD➣Cowden Disease
CD➣Collector, Dust
CD➣Claims, Defense
CD➣Convergence for Democracy
CD➣Channel Designator (US DoD)
CD➣Coffin Dancer
CD➣Competitive Design
CD➣Critical Defect
CD➣Contract Definition
CD➣Complete Divine (Dungeons & Dragons book)
CD➣Catalytic Distillation (petroleum refining)
CD➣Coordinated Delivery
CD➣Curriculum Differentiation
CD➣Concept Decision
CD➣Chain Delivery (printing press)
CD➣Combat Developer
CD➣Code Detector
CD➣Classification of Defects
CD➣Connectivity Date
CD➣Chained Declustering (computing)
CD➣Centrumdemokraterne (Danish political party)
CD➣Custom Delay
CD➣Command Director
CD➣Closed Document (number designator)
CD➣Command Decoder
CD➣Change Directive
CD➣Clock Distributor
CD➣Central Detector
CD➣Crimp Dies
CD➣Curative Dose
CD➣Canadian Decoration
CD➣Carterfone Decision
CD➣Capecitabine plus Docetaxel
CD➣Configuration Drawing
CD➣Charge Disproportionation
CD➣Contractual Data
CD➣Cervicodorsal
CD➣CoreDirector (Ciena)
CD➣Certificate of Design
CD➣Chaos Dwarves (gaming, Warhammer)
CD➣Corrected Depth
CD➣Command Discipline (NYPD)
CD➣Coordinating Draft
CD➣Canopy Destruct (ejection seat; US DoD)
CD➣Closed Drain
CD➣Cookie Dispenser
CD➣Circular Dichromism
CD➣Cold Dielectric (high temperature superconducting cables)
CD➣Courtesy Date
CD➣Contract Direction
CD➣Censorship & Documents (division in OSS)
CD➣California Detectives
CD➣Certified Drafter
CD➣Coolant Discharge
CD➣Coulomb Dipole
CD➣Crimson Deaths (counter-strike clan)
CD➣Choice Dividend
CD➣Certified Diamontologist
CD➣Containment Depressurization
CD➣Conventional Demodulation
CD➣Centralized Disbursing
CD➣Civil Emergency Preparedness Training (attendance code)
CD➣Completion Detector/Detection
CD➣Contractual Dependency
CD➣Covert Duress
CD➣Coat Dural (Mavic)

CD

Cd

CD

cd

cd

cd

Cd

CD

CD

Cd

cd

C.D.

Cd

CD

cd

CD

Cd,

CD:

CD

Cd

CD

candela

CD

cd

cd

CD

What Happened to the Phonograph?

CD

CD

Cd

CD

Cd

cd

CD

CD

CD

Cd

CD

CD

CD

certificate of deposit (CD)

CD

CD (1)

CD (2)

Certificate of Deposit

CD

Certificate of deposit (CD).

CD

CD

Cd

Synonyms for Cd

noun a soft bluish-white ductile malleable toxic bivalent metallic element

Synonyms

Related Words

noun the basic unit of luminous intensity adopted under the Systeme International d'Unites

Synonyms

Related Words

noun a debt instrument issued by a bank

Synonyms

Related Words

noun a digitally encoded recording on an optical disk that is smaller than a phonograph record

Synonyms

Related Words

adj being one hundred more than three hundred

Synonyms

Related Words