Short-term memory has a capacity than sensory memory and a duration.

Answer;
Short-term memory has a more limited capacity than sensory memory and a longer duration;

Explanation; 
Short-term memory is a limited-capacity memory system in which information is usually retained for only as long as 30 sec unless straggles are used to retain it longer.
It is limited in capacity but can store memory for a longer time
It is a way to improve short-term memory is through rehearsal; it lasts less than 30 sec without rehearsal.