IIS is a web server developed by Microsoft for Windows environments. Supports HTTP, HTTPS, FTP, SMTP, and NNTP protocols. Functions as a request-response server for web content delivery. Integrates with ASP.NET framework for web applications
NGINX is a lightweight web server for high-traffic use cases. Configuration files are located in /etc/nginx/ directory. Primary configuration file is /etc/nginx/nginx.conf
503 indicates website server is currently unavailable. Error can vary by website and server software. Usually occurs due to server overload or maintenance
Nginx consists of one master process and multiple worker processes. Configuration file is named nginx.conf and placed in /usr/local/nginx/conf. Number of worker processes can be fixed or automatically adjusted
Apache is a free, open-source web server located in conf directory. httpd.conf controls server-wide settings and contains various configuration sections. ServerRoot defines directory for logs and configuration files
Nginx is a popular web server available in Ubuntu's default repositories. Installation requires a non-root user with sudo privileges. Default installation includes Nginx and required dependencies