> For the complete documentation index, see [llms.txt](https://docs.rara.social/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rara.social/major-concepts/reactions.md). # Reactions Users [react](/protocol-features/react.md) to curate NFTs. Spending reactions enables users to add comments and tags to an NFT, too. Reaction can be used as: * Web3 emojis, likes, GIFs, and memes; * Filters for Photo NFTs; and * In-Game Consumables.

Web2 to Web3

Reactions are one-time use ERC-1155 tokens generated by the registered NFT’s media. Anyone can [register](/major-concepts/registration.md) an NFT they own as a reaction. We call these users "Makers". Once a reaction is registered, anyone can use it to curate an NFT via [react](/protocol-features/react.md). We call these users "Curators". Every time you react to an NFT, a free [RA! Like Token](broken://pages/MNi4f3RZ14LOpm3TZSuK) is generated. All curation and RA! like tokens are free! Transaction costs are generally only 1-2 cents in $MATIC.