Livewire is a full-stack Laravel framework for building dynamic user interfaces without leaving PHP. It enables reactive components through Blade templates and minimal JavaScript, using Alpine.js for frontend interactivity. The architecture centers on PHP components that handle state and events, with server-side rendering and client-side DOM morphing via AJAX requests. Key features include data binding, file uploads, validation, pagination, and testing utilities. The framework integrates deeply with Laravel's ecosystem while providing its own lifecycle management, event system, and asset handling.