JSX (JavaScript XML) is a syntax extension for JavaScript employed in React to depict the arrangement of UI components, a fundamental concept taught in Kaashiv Infotech's react js training in chennai.

It permits developers to craft HTML-like code within JavaScript files, facilitating the creation and visualization of the UI hierarchy, a skill covered extensively in the best reactjs course provided by Kaashiv Infotech.

JSX is not a distinct templating language but a syntax that undergoes conversion into regular JavaScript objects by tools such as Babel, a topic included in Kaashiv Infotech's react js online training.