All posts on PostPlaza are NFTs. Thus they can be bought, sold, and have an owner. Posts show the poster and the owner. The text content inside the post is stored on-chain, so it can never be tampered with or censored. Censorship can occur on the frontend displaying posts, but not on the post content itself.
NFP on PostPlaza
Images in posts are stored on IPFS. The IPFS hash is included inside the on-chain content.
Likes and reposts are stored in the form of events. A database holding all the likes and reposts can be built up by indexing all of the events emitted. Holding likes and reposts on-chain would be too expensive, so holding them as events is a cheaper alternative.
NFP on OpenSea
When a post is deleted, the on-chain data is removed and a Delete event is emitted. By listening for this event, indexers can remove a post when it is deleted. A post can only be deleted by the person who posted it, as long as they currently own it too.
Posts can also be created by directly interacting with the smart contract.
View a detailed description of the smart contract here.