Taxonomy
A vocabulary is a list of terms; a term is a thing content can be filed under. Categories, tags, statuses, manufacturers, material grades — anything you would otherwise be tempted to hard-code as a dropdown.
No hard-coded lists, anywhere
This is a rule of the platform, not a style preference. Every list a user might reasonably want to change is a vocabulary, seeded with sensible defaults and yours to edit. If you find a list you cannot edit, that is a bug worth reporting.
Vocabularies are bundles
A vocabulary behaves like a content type: terms have fields, displays, revisions and translations. A manufacturer term can carry a logo, a country and a website; a category can carry a hero image and an intro.
That is why a term is not merely a label — it is a record with an address of its own.
Hierarchy
Terms nest. A child term inherits its place in the tree, and a listing filtered by a parent can be told to include children — which is what makes "everything under Inverters" a single filter rather than a list of six.
Terms have pages
A term is reachable at its own address, and that page is a legitimate destination: a category page with its own text, image and a listing of what belongs to it.
The address comes from the platform, not from you
Never assemble a term URL by hand in a template or a token. Ask for the canonical address; an alias, a per-type rule and the plain form all resolve through it. Hand-built URLs are how a working link quietly starts pointing at the wrong kind of page.
Groups
Vocabularies can carry a group — a label that says which agenda they belong to. With thirty vocabularies in a mature installation, the group is the difference between a list you can read and a list you search.
Per organization
Vocabularies and terms belong to an organization. Two firms may each have a vocabulary called "Categories" with entirely different contents, and neither sees the other.
Translations
Term names are translated like everything else. A visitor reading in Slovak sees Slovak category names — in listings, in reference fields, in breadcrumbs and on the term's own page.
If a label appears in the wrong language
That is a bug, not a setting. Every public rendering of a term goes through the same translation lookup; one that does not is a defect and should be reported.