[moffkalast]

Afaik there's no difference, instruct and chat are used interchangeably. Mistral calls their tunes "modelname-Instruct", Meta calles them "modelname-chat".

Strictly speaking instruct tuning would mean having one instruction and one answer, but the models are typically smart enough to still get it if you chain them together and most tuning datasets do contain examples of some back and forth discussion. That might be more what could be considered a chat tune, but in practice it's not a hard distinction.