Network diagrams (or chart, or graph) show interconnections between a set of entities. Each entity is represented by a Node (or vertices). Connection between nodes are represented through links (or edges). The theory and realisation of network is a large field of research
in itself. A whole website could be dedicated to it. For example, network can be directed or undirected, weighted or unweighted. Many different input formats are available. To guide you in this field, I advise to follow the next examples in the proposed order, what should introduce
the concepts gradually. Note that datacamp offers a good course on network. Some real life examples are then proposed. Concerning the tool, I mainly rely on the NetworkX library. But note that the Graph Tool library should be considered as well, especially concerning high dimension networks.
NetworkX is a Python package for the creation, manipulation, and study of the structure, dynamics, and functions of complex networks. Its functioning is well described in its dedicated datacamp course.
The graph tool library is a python library implemented in C++. It makes it highly efficient to draw networks containing many nodes. Graphics to come.