Creating and using modules
Modules are a way of grouping functions for similar types of tasks or components into a common module. These modules can then be loaded, used, and unloaded together as needed. Modules are similar in concept to libraries in the Windows world—they are used to contain and organize tasks, while allowing them to be added and removed dynamically.
An example of a module is working with the DNS client. When working with the DNS client, you will have various tasks to perform: get configuration, set configuration, resolve hostname, register client, and so on. Because all of these tasks have to do with a common component, the DNS client, they can be logically grouped together into the
DNSClient module. We can then view the commands ...