Explanation

Function Invocations

The number of times your Serverless Functions received a request. This metric does not include Cache Hits.

When using Incremental Static Regeneration with Next.js, both the revalidate option for getStaticProps and fallback for getStaticPaths will result in a Function invocation. (throttled by the revalidate time)

Bandwidth

The amount of data your Deployments have received or sent. This metric includes traffic for both Preview and Production Deployments.

Outgoing: Outgoing bandwidth measures the amount of data that your Deployments have sent to your users.
All the responses from the Edge Network and Serverless Functions are collected as Outgoing bandwidth.

Incoming: Incoming bandwidth measures the amount of data that your Deployments have received from your users.

Image Optimization

If the same Source Image is used multiple times with different transformations, it is only counted once for the current billing period.