Hybrid and specialized topologies
As I mentioned before, most larger networks over which you might need to access resources are composed of multiple topologies joined together into what are typically called hybrids. A star topology, in which one of the peripheral nodes is also a link in a linear topology, would be an example of such a hybrid.
Other kinds of topologies are actually variants of the topologies we've discussed here. For example, a scenario where a node of a linear network topology is also the access point to a secondary linear topology constitutes a tree topology, simply a hierarchical linear topology. The specifics of these structures are less important than knowing that they exist and that, depending on the nature of the software you intend to deploy onto a network, you know that there are costs and considerations to be made for them. And speaking of those costs...