That's a very general question, but basically speaking, a short story is a short piece of fiction that generally includes the following elements: setting, characters, point of view, theme and plot.
The basic elements of poetry are the speaker, the use of lines and stanzas, rhythm and meter, rhyme, sound devices (alliteration, consonance, assonance and onomatopoeia), imagery and figures of speech (simile, metaphor and personification).
A drama is literature which is written to be performed, and therefore, the story is generally told through the words and actions of actors. The key elements of drama include characters, setting, plot, dialogue, and acts and scenes (as divisions of the drama).
This is a summary of information from the textbook "Literature: The Reader's Choice, Course 5," by Glencoe/McGraw-Hill, 1990.
Hope this helps. Good luck!