Which technique would provide the best performance for adding multiple DOM elements?
Using a DocumentFragment to batch DOM operations generally provides the best performance for adding multiple DOM elements. A DocumentFragment acts as a lightweight container that holds DOM nodes temporarily without being part of the actual DOM tree. The key performance benefit is that it minimizes DOM reflows and repaints by allowing you to construct and manipulate a complete subtree off-screen, then add it to the live DOM in a single operation. This results in only one reflow/repaint cycle instead of multiple ones that would occur when adding elements individually. While innerHTML can be fast for simple cases, it comes with security concerns (potential XSS vulnerabilities) and completely replaces existing content. DocumentFragment provides better performance with more flexibility and safety.