---
title: "Semantic web and its purpose"
subject: "Web Technology"
chapter: 9
key: "semester_7/web_technology:semantic-web-purpose-example"
source: https://www.bctengineer.com/q/semester_7/web_technology/semantic-web-purpose-example
site: BCT Engineering
---

# Semantic web and its purpose

Web Technology · Chapter 9: The Semantic Web

- Asked in: 2076 Chaitra, 2+3 marks; 2074 Asoj, 6 marks; 2074 Chaitra, 2 marks (asked 3 times)
- Video: [Intro to the Semantic Web](https://www.youtube.com/watch?v=OGg8A2zfWKg) — Manu Sporny
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/web_technology/semantic-web-purpose-example
- Whole chapter: https://www.bctengineer.com/md/semester_7/web_technology/chapter-9

## Question

What is Semantic Web? Explain the purpose of semantic web with suitable example.

## Short answer

The Semantic Web gives data explicit machine-readable meaning using RDF, OWL, and URIs, enabling automatic integration and reasoning. For example, a computer can query that Mount Everest has height 8848 m and is located in Nepal from RDF data, answering complex questions without human reading.

## Answer

#### Semantic Web
The **Semantic Web**, proposed by Tim Berners-Lee, is an extension of the current Web in which information is given well-defined **meaning** in a machine-readable form, so that computers can understand, share and combine data from different sources, not only display it. It uses technologies such as **URI, XML, RDF, RDFS, OWL, SPARQL** and ontologies.

```text
Layers: URI/Unicode -> XML -> RDF -> RDFS/OWL (ontology)
        -> Rules/SPARQL -> Logic, Proof, Trust
```

#### Purpose
- Make web data understandable by software, not only by humans.
- Allow automatic integration of data from many websites.
- Support intelligent agents that search, compare and make decisions for users.
- Give more accurate, meaning-based search results.
- Enable reuse and sharing of data across applications (Linked Data).

#### Example
A human reading "Mount Everest is 8848 m high and located in Nepal" understands it. A normal web page is just text for the computer. In the Semantic Web, the fact is written as RDF triples (subject-predicate-object):
```xml
<rdf:Description rdf:about="http://example.org/MountEverest">
  <ex:height>8848</ex:height>
  <ex:locatedIn rdf:resource="http://example.org/Nepal"/>
</rdf:Description>
```
Now a program asked "Which mountains in Nepal are higher than 8000 m?" can find the answer by itself. Similarly, a travel agent program could read flight, hotel and calendar data from different sites and book a trip automatically.

A keyword search for "jaguar" returns pages about both the car and the animal; with semantic markup the system knows which meaning is required.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the main idea of the Semantic Web?
   A. Make web pages look better
   B. Give information well-defined machine-readable meaning so computers can understand and combine data
   C. Make the web faster
   D. Replace HTTP with a new protocol
   Answer: B. It extends the Web so data has meaning that computers can process, not just display. (Key point: Semantic Web idea)

2. How is the fact 'Mount Everest is located in Nepal' represented in RDF?
   A. As a subject-predicate-object triple
   B. As a CSS rule
   C. As a plain paragraph of text
   D. As a JPEG image
   Answer: A. RDF represents facts as subject-predicate-object triples. (Key point: RDF triples)

3. Why can a program answer 'Which mountains in Nepal are higher than 8000 m?' when data is in RDF?
   A. It reads the page's colours
   B. The data has explicit meaning so the program can query it itself
   C. A human checks it first
   D. It uses keyword matching on titles
   Answer: B. With explicit meaning, a program can query the facts by itself. (Key point: Benefit of semantic data)

4. In the 'jaguar' example, what does semantic markup solve?
   A. Slow page loading
   B. Keyword search returning both car and animal; the system knows which meaning is needed
   C. Broken links
   D. Image compression
   Answer: B. Semantic markup disambiguates meaning where keywords cannot. (Key point: Ambiguity of keyword search)

## Related in Web Technology

- [Semantic web use, purpose and need](https://www.bctengineer.com/question.md?key=semester_7%2Fweb_technology%3Asemantic-web-need-use) — Web Technology, chapter 9
- [Main aspects of the Semantic Web](https://www.bctengineer.com/question.md?key=semester_7%2Fweb_technology%3Asemantic-web-aspects) — Web Technology, chapter 9