Focusing on word count:
* Haiku: A three-line poem with a strict syllable count (5-7-5), known for its brevity and evocative imagery.
* Tanka: A five-line poem with a syllable count of 5-7-5-7-7, offering more space for development than a haiku.
* Proverb: A short, well-known saying expressing a common truth or piece of advice, often packed with meaning.
* Aphorism: A concise, pointed statement expressing a general truth or observation, often witty or memorable.
Focusing on conciseness and impact:
* Flash fiction: Extremely short stories, sometimes only a few sentences long, that aim to create a strong impact with limited words.
* One-liner: A single, witty or insightful sentence that conveys a complete thought or idea.
* Epitaph: A short inscription on a tombstone, often a poetic tribute to the deceased, packed with meaning.
Ultimately, the "most compact" form depends on your individual definition of compactness. Consider what aspects of literature you value most (brevity, impact, symbolism, etc.) to determine the most appropriate form for you.