IIS
Servers & Server SoftwareIIS is Microsoft Internet Information Services, a web server platform for hosting websites and web applications on Windows Server. It handles HTTP/HTTPS requests, serves static files, and runs dynamic apps through modules and application pools. IIS integrates with Windows authentication, certificates, and management tools, making it a common choice for ASP.NET workloads and organizations standardized on Microsoft infrastructure.
How It Works
IIS runs as a set of Windows services that listen for web traffic and route requests to the correct site and application. The HTTP.sys kernel driver receives incoming connections, applies basic request handling, and passes work to IIS worker processes (w3wp.exe). Each website is configured with bindings (IP, port, host name, and TLS certificate) and points to a physical directory for content such as HTML, images, and downloads.
Dynamic content is executed through IIS features and modules. Application Pools isolate workloads by running sites in separate worker processes with their own identities, recycling rules, and resource limits. For ASP.NET and .NET apps, IIS integrates with the .NET runtime; for other stacks it can proxy to external processes via reverse proxy features. Administrators manage IIS through IIS Manager (GUI), PowerShell, or configuration files, controlling logging, compression, caching, URL rewriting, and security settings.
Why It Matters for Web Hosting
Choosing IIS affects which hosting plans and features will work for your site. If you need ASP.NET, Windows Authentication, or tight integration with Active Directory, you typically want Windows hosting with IIS rather than Linux hosting with Apache or Nginx. IIS also influences how you deploy (Web Deploy, PowerShell), how you configure rewrites and TLS, and what level of isolation and permissions you can expect on shared, VPS, or dedicated Windows servers.
Common Use Cases
- Hosting ASP.NET and ASP.NET Core applications on Windows Server
- Running internal business apps that use Windows Authentication or Active Directory
- Serving static websites and downloads with Windows-based management and permissions
- Hosting APIs and web services that rely on Microsoft tooling and deployment workflows
- Reverse proxying to application processes while keeping centralized TLS and logging
IIS vs Apache
IIS is tightly integrated with Windows (services, permissions, authentication, certificate stores, and management tools), which can simplify operations in Microsoft-centric environments. Apache is commonly used on Linux and is configured primarily through text-based directives, with broad ecosystem support across many distributions. For hosting decisions, the key difference is usually platform and application requirements: IIS aligns with Windows and many .NET-centric workflows, while Apache is a frequent default for Linux-based stacks and shared hosting environments.