AEM components are the modular units which realize specific functionality to present your content on your website.

Think of AEM components like building blocks for a website. Each component is a little piece of the website that does something specific, like showing text, an image, a button, or even more complex things like a slideshow or a contact form.

• Components are the Basic building blocks of the AEM website. They can be easily dragged and dropped to the pages
• Components are the reusable modules that implements specific application logic to render the content of our website
• Collection of scripts
• Modular and Re-usable unit

Web content management(WCM) have two components:

1. Core Components
2. Foundation Components

Core Components: Modern, flexible, and customizable components provided by Adobe for creating rich web content in AEM. Recommended for new projects.
Foundation Components: Older, less flexible components that are still available for legacy support. Less recommended for new projects but useful for maintaining older sites.