An elevator speech is a brief answer to a question about what
you do (or your company does) that is aimed at grabbing attention
from the listener so they want to follow up with you and find out
more.
It derives from the 30 seconds or so typically available to
answer the "what do you do?" question between floors in a elevator
ride.
It has a number of applications. Typically it is used by job
seekers to explain the sort of role they are seeking, businesses to
grab the attention of potential clients and referral partners, and
entrepreneurs seeking backers or investors (when it is typically
referred to as an elevator pitch). Other names for an elevator
speech include "30 second introduction" and "30 second
infomercial"