"WHY is about purpose, but it is much more than that. It is a tried and trusted technique to grab your audience’s attention at the beginning of your talk, and it provides a framework for you to start with a bang.
At its simplest, WHY stands for:
W - What is this presentation about?
H - Hooks – Why should people listen?
Y - Your aim – What is the goal or outcome you want? What is the action?
A compelling presentation will often start with these three elements towards the beginning. Sometimes they will be really obvious; sometimes less so. What you are aiming to do, however, remains the same: start your presentation strong and get the audience’s attention from the get-go.
I would personally recommend trying to cover these points in the first few sentences of your presentation. I believe it is important to set expectations clear from the beginning – and doing so in the first few sentences can set you up for success later on."