Modules can contain a single vocabulary taxonomy.
A good example module can be found at:
docroot/modules/custom/bos_vocab/modules/vocab_contact
Module naming convention is to call the module vocab_moduleName. The "moduleName" should be indicative of the taxonomy contained within the module.
{% hint style="success" %}
Sub-pages in this section assumes an example module is to be namedvocab_module_name - with module folder at:
docroot/modules/custom/bos_vocab/modules/vocab_module_name
{% endhint %}