Component-driven development is transforming the web
The web is undergoing a transformation: it was once page-based but is increasingly interactive and component-based. What, exactly, are components?
Is an image, or a title a component? No: these are elements on a web page. How about a set of elements, with a complex layout, like a “three-column layout with images,” that has responsive behavior for mobile devices? Still no. Call that a content block, or a layout block, perhaps.
So what makes a thing on a web page a component?
Components are like mini-applications, embedded in a web page. They can access remote resources, provide a small user interface, and can “do work.” So: an embedded YouTube widget is a component; a display helper for a PDF is a widget, or a “here’s the weather in your area” is a widget since it pulls data from another site, and maybe geo-locates the user.
are embedded on a web page, and delivered via a web browser;
are styled, hopefully, to look similar to the site itself;
have states, like loading, display, interactions, or error screens;
have a user interface, even if it’s a small “play” button on a video;
can connect to other systems via APIs, including local data or remote servers and data stores;