Not exactly... within JSX the handlebars signify "now I'm going back to plain JS".

compare

    <div>
        console.log(123)
    </div>

with

    <div>
        { console.log(123) }
    </div>

The first outputs a div with the text "console.log(123)" inside. The second logs "123" and outputs an empty div (since console.log returns undefined).