A professional summary is just that--a summary
of your content, usually found at the beginning
of a resume or CV to quickly create alignment
with the position or organization of interest.
Use this section to quickly establish: "Who
you are", "What you know", "How you do it", and
"Why it is important" to the reader.
Let’s break that down.
When explaining, "Who you are"--
clearly show your qualifications.
This could be seen in the degrees and
specialized certificates you have earned.
For, "What you know"--showcase your knowledge
of unique areas of expertise
and specialized population groups.
"How you do it" focuses on your skills & attributes. 
Pick 1 or 2 top skills or attributes
that are linked to the job description.
This will be a snapshot into how you will perform as a future employee.
The most important part of a professional summary
is why.
This is where you create alignment through
showing how you will help the organization
and team accomplish their goals.
You can also talk about your passion,
which is the why behind what you do,
and how it resonates with the mission
and values of organization.
In conclusion, a well written professional summary will
clearly communicate your fit to the organization
and position,
identify the skills wanted in a potential
candidate, and
entice the reader to spend more time on your
resume or CV.
