Online Social Networks — The Basics

Exhibit 25.41 Nodes and edges.

Social networks are defined by two components: nodes and edges. (Refer to Exhibit 25.41). Nodes represent elements like users, content, or pages, while edges represent the relationships between these nodes, such as friendships, comments, or shares.

For instance, in the case of a user, say Diana, in a network, other users can be related as followers, friends, or mutual friends.

• Followers are the users who follow Diana.
• Friends are those whom Diana follows.
• Mutual friends are users who both followers and friends, i.e., they fall in the intersection between the two groups.

Social networks can be:

• Undirected: Both nodes have a reciprocal relationship (e.g., two users connected because they attended the same university).
• Directed: The relationship is one-way (e.g., a Twitter user following another without being followed back).

Networks also vary by their structure:

• Unimodal Networks: Contain a single type of node (e.g., users only).
• Multimodal Networks: Include multiple types of nodes (e.g., users and posts).