This document defines common terms used in website design and development. It explains what a webpage, website, web browser, domain name, URL, HTML, CSS, favicon, nesting, hyperlink, title attribute, alt attribute, call to action, hero image, promo area, exit page, input field, white space, SEO, and CMS are. Key terms include HTML and CSS being languages used to structure and style webpages, a domain name being the text address of a website, and SEO being the process of optimizing a website to increase its visibility in search engines.