A graph is something that is used to create an abstract representation of real world situation. Now that sounds very fancy, but it's actually a very simple structure. A graph consists of nodes which represent a certain object or concept, and of links or relations that connect these nodes.
So this doesn't look very meaningful. Just some dots and some lines. But those dots represent something else. Take the following example:
This is already a bit more meaningful, right? We can see that there is some sort of connection between something called Daniel Termont and another thing called Ghent. Now, we can make this even more meaningful by adding some labels:
We have labelled Daniel Termont as a person, and Ghent as a Location. Hence the nice looking icons! So, as you can see, it's a very simple simple structure that is very flexible and very useful in describing situations. It's also a much more efficient way of storing information compared to documents. Let's save that for the next blog post.
So, a graph can have nodes, with or without labels, and relationships connecting these nodes. What else?
Well, like we said before, a node represents something from the real world. So they can have many different properties. For example a person will have a name and a birthday. And a city will have a number of inhabitants. Using Gloow, you can neatly save these properties on your nodes, or even on your relationships:
So, let's summarise what we've learned in a graph:
So, now you know it, a knowledge graph is a merely a graph that contains knowledge.
However, it is a very powerful system that we can use to organise our information. It allows you to directly see how one concept is related to another, and give you insights that you would otherwise miss. Because of its structured nature, it's also much easier for computer systems to process info in a graph, than it would be it was for example in unstructured documents.
With Gloow we provide an online service that allows you to create, manage and query your own knowledge graphs.