Post types
Post types are the categories your space files its posts under — News, Article, Announcement, whatever your space publishes. They belong to your space rather than to the platform, so you define the set you need, and a post carries at most one of them. The type is what lets readers filter the post listing by category.
They are managed in Settings → Post types, also reachable from Settings → General → Discussions. Managing them needs permission to change content.
Add a type
Open Settings → Post types.
Press Create.
Enter the Name — the category as readers will see it.
Add a Translation for each language your space publishes in: a language and the name in that language. Add as many as you need.
Save.
The type is then offered in the Type field of every post editor.
Rename or remove a type
Edit opens the same form, and the type is saved as a whole — the translations left in the form are the translations it keeps. Posts refer to their type by its identity rather than by its name, so renaming a type keeps every post filed under it. That is the safe way to change how a category reads.
Delete removes the type from the space after a confirmation.