A private channel is represented through Slack's unified conversation-object model. Slack's Conversations API consolidates several historically separate object categories into the conversation abstraction. Depending on its properties, a conversation object can represent a public channel, private channel, direct message, multi-person direct message, and other conversation-oriented constructs. For a private channel, the conversation object exposes properties such as is_private. Slack's modern APIs therefore avoid requiring developers to treat every channel type through entirely separate legacy APIs. Older terminology such as group survives in some legacy documentation and fields, but private channels are now handled through the Conversations API. A public message is not itself a conversation; it is content contained inside a conversation. A message reaction is metadata or an event associated with a message. A file attachment similarly represents content attached to or referenced from a message rather than a conversation container. The distinction matters when using methods such as conversations.info, conversations.list, conversations.history, and other Conversations API operations because the same core object model can represent multiple Slack conversation types. This maps to Apps in the Slack Platform, specifically understanding Slack's object model and the unified Conversations API.