What are Web Components and what standards make them up?

Web Components are a suite of native browser standards that enable creating reusable, encapsulated HTML elements. They consist of three main specifications: Custom Elements: define new HTML tags with custom behavior using customElements.define("my-button", MyButtonClass). The class extends HTMLElement and can implement lifecycle callbacks (connectedCallback, disconnectedCallback, attributeChangedCallback). Shadow DOM: encapsulate the internal structure and styles within a shadow root, preventing style leakage. HTML Templates: <template> and <slot> elements define reusable, inert HTML fragments and slots for external content. Web Components are supported natively in all major browsers and work with any framework or no framework at all.