I think you're mixing some things up there.

The history of making HTTP requests in the browser has only been two APIs: XMLHttpRequest -> fetch. Fetch is an upgraded version of XMLHttpRequest with a promise-based API and better async/streaming support.

Ajax was a word used to describe the technique of making http requests in the browser, and axios is a third party library that wraps different APIs on different platforms to provide a unified interface. These were never separate browser APIs.