Zapier is an app automation tool that connects to over 1,400 apps, allowing businesses to automate their workflows and processes by pairing it with all-in-one platforms like HubSpot, which offers marketing, sales, customer service, and customer relationship management (CRM) software. By leveraging Zapier and HubSpot, companies can streamline their operations, reduce manual effort, and improve productivity, as seen in the success stories of Love Your Melon, Olark, and Taylor and Hart, who have automated various aspects of their businesses using Zaps to integrate with HubSpot and other apps.