A web server is a computer system (hardware) running software that serves web content to users over the internet. When you visit a website, your browser sends a request to a web server, which responds with the requested files (HTML, CSS, JavaScript, images).
Hardware vs. Software
Web server hardware: The physical or virtual machine hosting your website.
Web server software: Programs that handle HTTP requests and serve content.
Popular Web Server Software
Nginx
- High performance, low memory usage
- Excellent for static files and reverse proxy
- Used by Netflix, WordPress.com, Dropbox
- Most popular web server today
Apache
- Oldest major web server (since 1995)
- Highly configurable with modules
- .htaccess files for directory-level config
- Still powers many WordPress sites
LiteSpeed
- Commercial server, high performance
- Apache compatibility
- Built-in caching
- Popular for WordPress hosting
Caddy
- Automatic HTTPS
- Simple configuration
- Growing in popularity
- Great for modern applications
IIS (Internet Information Services)
- Microsoft's web server
- Windows-only
- Used for .NET applications
What Web Servers Do
Serve Static Files
HTML, CSS, JavaScript, images. Files that don't change.
Process Dynamic Requests
Pass requests to application code (PHP, Node.js, Python) and return results.
Handle Connections
Manage thousands of simultaneous connections efficiently.
Security
Control access, handle SSL/TLS, block malicious requests.
Logging
Record requests for analytics and debugging.
Caching
Store frequently-requested content for faster delivery.
Server Architecture Patterns
Single Server
Everything on one machine. Simple but limited.
Load-Balanced
Multiple servers behind a load balancer. Better reliability and performance.
Microservices
Different services on different servers, communicating via APIs.
Serverless
No dedicated server. Functions run on-demand (AWS Lambda, Cloudflare Workers).
Choosing Server Resources
CPU
More cores = handle more requests simultaneously.
RAM
More memory = faster response, more concurrent users.
Storage
SSD is much faster than HDD. Size depends on content.
Bandwidth
Data transfer capacity. High-traffic sites need more.