Web Components are a suite of different technologies that allow developers to create reusable custom elements — with their functionality encapsulated away from the rest of the code — and utilize them in web applications. The main goal of Web Components is to enable the creation of highly reusable and encapsulated HTML tags that can be used in web pages and web applications.
Main Technologies in Web Components
Custom Elements: These are a set of JavaScript APIs that allow you to define custom elements and their behavior, which can then be used as desired in your user interface. Custom elements can be either autonomous custom elements, which are entirely new elements, or customized built-in elements, which extend existing elements[1][10].
Shadow DOM: This technology provides encapsulation for the JavaScript and CSS of a component. The Shadow DOM API allows hidden DOM trees to be attached to elements in the regular DOM tree — this shadow DOM tree starts with a shadow root, under which can be attached to any elements you like, much like the normal DOM[1][10].
HTML Templates: The <template> and <slot> elements enable you to write markup templates that are not displayed in the rendered page. These templates can be reused multiple times and are instantiated via JavaScript. <template> stores the markup while <slot> allows you to define placeholders within your template that can be filled with any markup fragment when the element is used within a document[1][12].
Advantages of Using Web Components
Encapsulation: Styles and scripts defined inside a shadow DOM are scoped to the element and do not clash with other parts of a document.
Reusability: Components are designed to be reusable, which can simplify the development process and reduce code redundancy.
Interoperability: They can be used across modern browsers and can be easily integrated with other web applications and frameworks[1][3].
