/ˈæp-tʃi/
n. “The web server that started the modern web.”
Apache, formally known as the Apache HTTP Server, is a free, open-source web server software that serves web content over the HTTP and HTTPS protocols. It has been one of the most popular web servers since the mid-1990s and is widely deployed for hosting websites, web applications, and APIs.
Apache is known for its modular architecture. Core functionality can be extended through modules, which enable features like URL rewriting, authentication, SSL/TLS encryption, proxying, logging, and caching. This modularity allows administrators to tailor the server to their specific needs without bloating performance.
Key characteristics of Apache include cross-platform compatibility, robust performance, and strong community support. It runs on Linux, UNIX, Windows, and macOS, integrates with various programming languages like PHP, Python, and Perl, and can serve both static and dynamic content.
Here’s a simple example demonstrating a basic Apache configuration snippet to host a website:
<VirtualHost *:80>
ServerName example.com
DocumentRoot /var/www/html/example
<Directory /var/www/html/example>
Options Indexes FollowSymLinks
AllowOverride All
Require all granted
</Directory>
ErrorLog ${APACHE_LOG_DIR}/example_error.log
CustomLog ${APACHE_LOG_DIR}/example_access.log combined
</VirtualHost>This snippet sets up a virtual host for example.com, specifying where the website files are located and configuring access permissions, logging, and directory behavior.
In practice, Apache powers countless websites and applications, often paired with MySQL or PostgreSQL and application frameworks to form the classic LAMP stack (Linux, Apache, MySQL, PHP/Python/Perl).
In essence, Apache is a reliable, flexible, and battle-tested web server that continues to serve as the backbone for a significant portion of the internet.