Here are some of the different concepts you can find in Happeo.

Channels

These group posts, articles & some integrations like Google Drive & Calendar. The access management rights are done on a channel level. A channel can have an owner (user), editors who can manage the channel, and participants (both users and/or groups).

Posts

A post is a type of content usually used in a discussion. A post can contain attachments, have comments and have reactions. You can have personal drafts, shared drafts (with channel editors) or published content. A post can be shared as an announcement, which means the channel members need to tick a box to mark it as read.
A post belongs to only one channel.

Posts have two layouts: ARTICLE & POST. The ARTICLE layout is meant for longer content, while the POST layout is meant for shorter content.

Comments

A user can write a comment on posts. A comment can have reactions and attachments.

Pages

Pages are the Happeo equivalent of a static intranet. They are static content with complex layouts and widget structures. There will not be an API provided to access Pages.

Users

People or system accounts / bots. Everything is done by users. Posts have authors, channels have creators, etc. The API will only provide a way to list users and manage their licenses at first.

Groups

Currently only synced from G Suite. A Group is a collection of Users, usually used for channel or page sharing purposes. No API, as they are completely synced from G Suite.