The Pixel fires standard events (such as Lead, Purchase, AddToCart, and CompleteRegistration) and custom events when visitors take actions on your site. Meta uses that data to report conversions, optimize delivery toward people likely to convert, and build website Custom Audiences for retargeting.
Because the Pixel runs in the browser, it's affected by ad blockers, browser privacy features, and consent choices, so on its own it misses a meaningful share of conversions. Meta recommends pairing it with the Conversions API and deduplicating events that both send, so measurement stays accurate.
Example
When a visitor submits a quote request, the Pixel fires a Lead event, which Meta credits to the ad they clicked and uses to find more people likely to request quotes.
How Sloss Digital uses it
We install the Pixel through Google Tag Manager with consent controls, map clean standard events, and always pair it with the Conversions API.