left click : rotate
right click : pan
scroll : zoom
hover over node : previews the Wikipedia article corresponding to the node
node left click : navigate to node and center rotation axis around node
node right click→Show Connected Articles: shows the connections to an article
node right click→Expand Network Using Article: adds more articles to the network using the right clicked article as a starting point
node right click→Open Article in New Tab : opens the right clicked article in a new tab
You can think of Wikipedia as a directed graph where an edge from article A to article B signifies that article B is a hyperlink in article A. In this sense, the network articles displayed in this program is a bounded breadth first search of the graph of all Wikipedia articles starting from the article you enter in the search bar.
You can view the edges connected to a node by right clicking it and selecting Show Connected Articles and extend the breadth first search starting from a node by right clicking it and selecting Expand Network Using Article.