Many sources, including official tutorials and guides, often describe  JSX as "JavaScript XML", but the  official React documentation doesn't explicitly define JSX that way.

What JSX Actually Is:

JSX is a syntax extension for JavaScript that looks similar to XML or HTML but is ultimately  compiled into JavaScript. React's official documentation describes it as:

JSX is a syntax extension for JavaScript. It is used with React to describe what the UI should look like. React Docs

While JSX resembles XML/HTML, it's not exactly the same, and React itself doesn't formally call it "JavaScript XML." Instead, JSX gets  transpiled into JavaScript function calls using Babel.

For example:

jsx

 const element = Hello, JSX!;

Compiles to: Js code

 const element = React.createElement("h1", null, "Hello, JSX!");

Why Is It Called "JavaScript XML"?

1. The term  JavaScript XML (JSX) likely became popular because JSX  looks like XML  and is used to structure UI elements.

2. However,  JSX is not XML—it just borrows some of its syntax.