Nodes and Edges
Every network is made up of nodes and edges. Nodes represent points of data on the map, and these points of data are connected to each other by Edges (also called Links). For example, in the network image below there are three investors (Worldview, Allegis, and Hummer Winblad) shaped like ovals and two companies (QueueCard and ActiveGrid) shaped like boxes. The ovals and the boxes are all nodes. The different shapes tell us information about what types of nodes they are. The investor ovals have links with arrows pointing to the companies. These links give us more information. They represent capital investment into the companies by the investors.
Map 1.1 - ActiveGrid Relational Bipartite (companies & investors)
Nodes in a map are data points, and edges describe how they are linked to one another. In simple networks all of the edges represent the same type of connection between nodes, so every link in the network represents the same type of relationship. In the simple network pictured above, each of the five links in the network represents a capital investment from an investor into a company. However, in more complex maps there can be different kinds of links that represent different kinds of connections.
The complex network below is a different way of looking at the same network in the example above. In this example there are new types of nodes and links present. Notice the pink nodes that represent Individual People (either Board Members or Management Team Members), as well as the colored edges that indicate different types of connections between nodes. Board Members do not define their connections to a copmany in the same way as an investor, through capital investment, so it makes sense that their links would have different colors to show their connections. Furthermore, there are two colors of links that connect the people (Pink Ovals) to the companies (Blue Squares) because some of the connections represent Board Members (like Mitchell Kurtzman) and others represent Management Team Members (like Larry Abrahams).
Map 1.2 - ActiveGrid Relational Tripartite
Later in the Tutorial you will learn what the colors and shapes of nodes and edges represent for the different types of maps, but first it is important to understand the basics of reading networks. For example, try to find all of the pieces (each node and edge) from Example 1 in Example 2. Do you see how the entire network in Example 1 is present in Example 2, but that it is the addition of other nodes and edges that makes their appearances different?