# Graphs in computer science and the real world

**Lesson title:**Graphs in computer science and the real world**Keywords:**Graph, Node, Edge**Objective/Description:**In this lesson We will learn about graphs, what they are and how they are relevant to knowledge representation. We will also see how they relate to the Semantic Web.-
**Learning outcomes:**- Describing what a graph is and its main components
- Illustrating via examples the use and importance of graphs for knowledge representation
- Explaining the relevance of graphs in the semantic web
- Using graph structures to model real life statements

## Resources

## Questions and answers

These Q&A aim to validate a basic understanding of concepts discussed during the lecture. The use of such concepts is beyond the scope of this Q&Astudy set as it is addressed via projects and hands-on for those enrolled in the corresponding university course.

What is a graph?

A graph is a structure consisting of nodes and edges (which connect nodes to each other).

What is an acyclic graph?

A graph where there is no path from any node to itself.

Example A - B, B - C

Example A - B, B - C

What is a cyclic graph?

A graph where there is at least one path from one of its nodes to itself.

Example A - B, B - C, C - A (cyclic path would be A - B - C - A)

Example A - B, B - C, C - A (cyclic path would be A - B - C - A)

What are some examples of graphs?

A metro (aka tube or undergraound) network.

An organigram.

The tree of life.

An organigram.

The tree of life.