We have a feature called Access Control List (ACL), with this you can create
a user groups and assign them permissions to access, create, edit or delete
content or modify certains parts of your site like articles, categories, modules,
global configurations, etc.

When you create for example your category, you can assign a user group in
the Permissions Tab.

Here some docs: https://docs.joomla.org/ACL

Here a full example: https://docs.joomla.org/J3.x:Access_Control_List_Tutorial

Best Regards!

We have a feature called Access Control List (ACL), with this you can create
a user groups and assign them permissions to access, create, edit or delete
content or modify certains parts of your site like articles, categories, modules,
global configurations, etc.

For example, we have the user group "Author", in the screenshot you can see a 
category called "Blog", in the "Permissions" tab we can allow or denied actions.

Here some docs: https://docs.joomla.org/ACL

Here a full example: https://docs.joomla.org/J3.x:Access_Control_List_Tutorial

Best Regards!