# IIS (Internet Information Services)

**IIS**, short for **Internet Information Services**, is a web server software developed by **Microsoft**. It is designed to run on **Windows operating systems** and is used to host and manage web applications, websites, and services over the internet or an intranet.

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## What is IIS?

IIS is a **feature-rich** and **secure** web server that supports multiple protocols such as **HTTP**, **HTTPS**, **FTP**, **FTPS**, **SMTP**, and more. It is deeply integrated with the Windows ecosystem, making it the go-to choice for hosting applications built with **ASP.NET**, **.NET Core**, and **Classic ASP**.

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## Key Features of IIS

- **Graphical Interface**: Manage websites and services using an intuitive GUI.
- **Application Pools**: Run multiple applications independently in isolated pools.
- **Security**: Built-in Windows authentication, SSL certificate management, request filtering.
- **Logging and Diagnostics**: Real-time monitoring and detailed logging capabilities.
- **Extensibility**: Add or remove modules like URL Rewrite, WebDAV, and more.
- **PowerShell Support**: Automate IIS tasks using scripts.
- **FTP and SMTP Support**: Supports multiple protocols for file transfer and mail delivery.

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## IIS Use Cases

1. **Hosting ASP.NET and .NET Core Web Applications**
   - Primary choice for enterprises using the Microsoft tech stack.

2. **Intranet Portals**
   - Secure, internal company portals integrated with Active Directory.

3. **Static and Dynamic Website Hosting**
   - Serve both static files (HTML/CSS/JS) and dynamic content (using .NET/ASP).

4. **FTP Server**
   - Securely share files over the network using the built-in FTP server.

5. **Web Services/API Hosting**
   - Host RESTful APIs built using .NET technologies.

6. **Load Balancing & Reverse Proxy (Limited)**
   - Can act as a reverse proxy with URL Rewrite and ARR (Application Request Routing) module.

7. **PowerShell and WMI Integration**
   - Automate deployments and server configuration.

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## IIS vs NGINX

| Feature                    | IIS               | NGINX                           |
| -------------------------- | ----------------- | ------------------------------- |
| Platform                   | Windows-only      | Cross-platform (Linux, Windows) |
| GUI Management             | Yes (IIS Manager) | No (CLI and config files)       |
| Performance (Static Files) | Moderate          | High                            |