# optical disc reader

> optical disc drive that supports reading but not writing

**Wikidata**: [Q363902](https://www.wikidata.org/wiki/Q363902)  
**Source**: https://4ort.xyz/entity/optical-disc-reader

Here’s the structured knowledge entry for **optical disc reader**:

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## Summary  
An optical disc reader is a type of optical disc drive that supports reading data from discs but cannot write to them. It is commonly used for accessing pre-recorded media like CDs, DVDs, or Blu-ray discs. Examples include CD-ROM drives, DVD readers, and BD-ROM drives.

## Key Facts  
- **Subclass of**: Optical disc drive (a disk drive that uses laser light or electromagnetic waves to read or write data).  
- **Opposite of**: Optical disc writer (a drive capable of writing data to discs).  
- **Characteristics**: Read-only memory (cannot modify data on discs).  
- **Common aliases**: CD reader, DVD reader, 光ディスク読み取り装置 (Japanese).  
- **Supported formats**: CD-ROM, DVD, BD-ROM (depending on the drive type).  
- **Wikidata description**: "Optical disc drive that supports reading but not writing."  
- **Sitelink count**: 2 (indicating limited Wikipedia coverage).  
- **Google Knowledge Graph ID**: `/g/121xqcfp`.  

## FAQs  
### Q: What is the difference between an optical disc reader and an optical disc writer?  
A: An optical disc reader can only read data from discs, while an optical disc writer can both read and write data (e.g., burn CDs or DVDs).  

### Q: Can an optical disc reader play movies from DVDs?  
A: Yes, a DVD reader can play movies from DVDs, as it is designed to read pre-recorded disc content.  

### Q: Are optical disc readers still used today?  
A: While less common due to streaming and USB storage, they are still used for accessing legacy media, software installations, or archival data.  

## Why It Matters  
Optical disc readers played a critical role in data distribution and multimedia consumption before the rise of digital downloads and cloud storage. They enabled widespread access to software, music, movies, and archival data stored on CDs, DVDs, and Blu-ray discs. Though their usage has declined, they remain important for legacy systems, physical media enthusiasts, and industries relying on disc-based data. Their read-only functionality also ensured data integrity for pre-recorded content.  

## Notable For  
- **Read-only functionality**: Unlike combo drives, they cannot write data, making them simpler and more reliable for playback.  
- **Format support**: Includes specialized drives like CD-ROM, DVD, and BD-ROM readers.  
- **Historical role**: Dominated software distribution and media playback in the late 20th and early 21st centuries.  

## Body  
### Types of Optical Disc Readers  
- **CD-ROM drive**: Reads compact discs (CDs) only.  
- **DVD drive**: Reads DVDs, often backward-compatible with CDs.  
- **BD-ROM drive**: Reads Blu-ray discs, sometimes supporting DVDs and CDs.  

### Technical Characteristics  
- **Function**: Uses lasers to read pits and lands on disc surfaces.  
- **Read speed**: Varies by format (e.g., 24x for CDs, 16x for DVDs).  
- **Compatibility**: Some drives support multiple formats (e.g., DVD/CD readers).  

### Historical Context  
- **Decline**: Usage decreased with USB drives, streaming, and downloadable media.  
- **Legacy use**: Still found in older computers, gaming consoles, and professional archives.  

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