Zapier is a web-based service that allows end-users to integrate the web applications they use and automate workflows. It enables users to create 'Zaps', which are automated tasks that connect two or more apps to complete specific functions. For example, a Zap could automatically save email attachments from Gmail to Dropbox and then alert the user in Slack about the new file. Zapier supports thousands of apps, allowing for a wide range of automations that can save time and reduce the need for manual data entry or task management. It's particularly valuable for businesses and individuals looking to streamline their digital processes and enhance productivity.