Lightning Web Components (LWC) is a programming model and component-based framework provided by Salesforce.com for building custom web components and applications within the Salesforce platform. LWC uses modern web standards such as JavaScript and HTML to create reusable UI components that interact with Salesforce data and services. LWC provides features for data binding, event handling, lifecycle hooks, and component composition, enabling developers to build fast, responsive, and scalable web applications.