EJS (Embedded JavaScript) is a templating engine that allows developers to embed JavaScript code into HTML documents. The resulting HTML documents are then rendered by the browser, with the JavaScript code executed and replaced by the corresponding output.

Using EJS, developers can create dynamic and interactive web pages by combining the power of JavaScript with the simplicity of HTML. EJS also allows for the creation of reusable templates, which can be rendered with different data sets to produce different results.

The basic syntax of EJS consists of special tags that are used to embed JavaScript code into HTML. These tags are typically <% %> or <%= %>. The first type of tag, <% %>, is used to execute JavaScript code, while the second type, <%= %>, is used to output the result of the JavaScript code.