# Intro ## Objectives * Describe jQuery and its purpose as a JavaScript library * Discuss the benefits and drawbacks of using jQuery. * Practice using jQuery selectors ### What is jQuery? jQuery is a free, open-source, 3rd-party library that is intended to make front-end development tasks --- particularly those involving DOM selection and manipulation --- easier, faster, and more fun. ### But wait, what do we mean by 'library'? **A `library`** is a collection of reusable functions that serve a particular purpose. The great thing about libraries is that we're using code that solves common problems, thus avoiding *reinvention of the wheel*. ### Why use it? * simplifies complex DOM manipulation * concise, intuitive, readable syntax also * solves many cross-browser compatibility issues for us * fun and super helpful jQuery plugins * well-maintained, issues resolved quickly * designed for developers to implement complex functionality quickly and easily * makes css changes and javascript animation very simple ### Cons? * jQuery is much slower than vanilla javascript in many cases (it solves so many issues so it runs a LOT of code behind the scenes) * constantly evolving, so you need to keep up and understand a lot about how it works in order to be able to resolve any issues you encounter when implementing jQuery * in conclusion: good for readability, bad for debugging --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://romebell.gitbook.io/sei-1019/jquery/jquery-intro.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.