A template engine in Express is a module that facilitates the generation of dynamic HTML content by embedding dynamic data into static templates. The following steps outline the process of using a template engine in Express:

1. Install a Template Engine Module: Install the desired template engine module using npm. Popular choices include "ejs," "pug," and "handlebars." bash npm install ejs

2. Set Up Express to Use the Template Engine: Configure Express to use the installed template engine. This involves requiring the module and setting it as the view engine. ```javascript const express = require('express'); const app = express();

app.set('view engine', 'ejs'); ```

1. Create Template Files: Create template files with the appropriate file extension (e.g., ".ejs"). These files contain HTML code with embedded placeholders for dynamic data. ```html

Welcome to <%= appName %>

```

1. Render Templates in Routes: In Express routes, use the render method to render the specified template and pass dynamic data to it. javascript app.get('/', (req, res) => { res.render('index', { pageTitle: 'Home', appName: 'MyApp' }); });

2. Dynamic Data in Templates: Within templates, dynamic data is embedded using template engine-specific syntax. For example, in EJS, <%= variable %> is used to embed a variable's value. ```html
   

   Welcome to <%= appName %>

```

1. Response to the Client: The rendered HTML, containing the dynamically generated content, is sent as the response to the client. ```html
   

   Welcome to MyApp

```

By following these steps, dynamic content can be easily generated and served in response to client requests using template engines in Express.