Webhook capture all incoming messages from your phone then picky assist bridge mobile app extract the messages and pushes into webhook URL configured, i.e when a new incoming message arrives in your whatsapp or SMS the bridge app extract the information from your phone and push to your webhook.
This is a global webhook which capture all incoming messages in your project from all configured channels
Settings -> Webhook - Global Webhook
This can be set along with Smart Replies , if smart replies webhook are enabled then global webhook will not be triggered
Smart Replies -> Settings -> Webhook
This can be set to capture all events like Delivery Report, WhatsApp Filter Report, New Subscriber Alert etc
Settings -> Webhook -> Event Webhook