An elevator speech can be defined as:

A speech that you can reuse in almost any professional situation, a sales pitch.

A speech that you can give during an interview that explains how you think you can "reach the top" if you get the position.

A drawn out, formal presentation, that focuses on just yourself and lasts for $1$ minute or more.

A clear, brief message or "commercial" about you that lasts no more than $30$ seconds and communicates who you are, what you are looking for, and how you can benefit a company or organization.