What are Webhooks and how to use them in Strapi

Hi, i am new to strapi and couldn’t understand how to use webhooks.

Requirement: whenever admin adds a content in collection (notifications), the event should be triggered with the latest data(eg: we are back with new offers) and it should be visible on react/next js website without refreshing the webpage.

We have created the webhook. But do we subscribe to the data that is sent from it?

Do we need another api endpoint for it?