mesyeti
Web
The web is an information system allowing you to view pages. Pages are made up of HTML, a markup language using the XML syntax which is used for describing the content of the page. They can optionally use the CSS markup language to describe the appearence of the page, including things like font, text colour, etc. They can also use the JavaScript programming langauge for client side scripting. The Web also uses the HTTP protocol.
JavaScript
JavaScript is a programming language made by Brendan Eich in the span of 10 days. The Callisto programming language was "completed" in a similar amount of time (12 days) and at that point, Callisto was probably worse than JavaScript. While Callisto improved over the next year, JavaScript is sadly still terrible.
(I'm not serious, it just has many quirks.)
My actual criticism for JavaScript is its impact on the web. Simple pages (like this one) don't need JavaScript. Nothing is really happening on the page, it's just a document. Many simple pages end up having JavaScript on them anyway because they are made using frameworks or made by website making tools that add JavaScript. This is excessive and it would be fair to call them bloat. The main big issue with JavaScript is that it is being used with web technology to create applications. Applications using web technologies are the absolute worst for resource usage.
For an extended version of what I was saying above, see the bloat page.