What is jQuery, and is it still relevant today?

Summary

jQuery is a JavaScript library (first released in 2006) that simplified DOM selection and manipulation, events, animation and AJAX, and smoothed over browser inconsistencies. Modern browsers now provide most of this natively (querySelectorAll, classList, fetch, addEventListener), so new projects rarely need it, but it still runs on a large share of existing websites, including WordPress themes and many legacy business applications.

Longer Answer

Where jQuery remains relevant: maintaining and extending legacy applications, CMS ecosystems (WordPress, Drupal and their plugins), and small enhancements on server-rendered pages where adding a framework would be overkill. In interviews it usually signals a role that maintains an existing codebase, so expect questions about safe maintenance, performance, security updates and gradual migration.

For new interactive applications teams typically choose a component framework (React, Vue, Svelte) or lightweight progressive-enhancement tools (Alpine.js, htmx).

Key Points

• DOM, events, AJAX, animation helper library.
• Browsers now cover most of it natively.
• Still common in legacy apps and CMSs.
• Maintenance and migration skills matter.

What interviewers look for

A realistic view: knowing jQuery well, knowing its modern equivalents, and judging when to keep or replace it.