Pixels and customer events
Pixels are JavaScript code snippets that run on your online store, customer accounts pages, or store checkout and collect and pass behavioral customer data for marketing and analytics.
Pixels can be added to your online store in 2 ways: through app pixels, which are installed through marketing and data collection apps, and custom pixels, which can be manually added by a developer in the pixels manager of your Shopify admin. When possible, choose an app pixel integrated with a third-party service to leverage higher security and include automatic updates. If there isn't an app pixel available that meets your requirements, then you can use custom pixels on your store to track customer events. You can install available app pixels from the Shopify App Store.
Pixels are managed from the Customer events section in your Shopify admin. Customer events are actions taken by your customers, such as clicking a link or adding a product to the cart, that can help you understand how your customers are engaging with your business. Third-party services that are integrated with your store use the customer event data that they collect using pixels to optimize your marketing automations and analytics.