Apache HTTP Server: process-based architecture
Apache HTTP Server uses by default the MPM (Multi-Processing Module) prefork or worker. With prefork, each incoming request is served by a dedicated process, simple and stable but memory-hungry (each process = a few MB). With worker (or event), Apache uses a process + thread mix to reduce consumption. Configuration is done via the httpd.conf file and the local .htaccess files that Apache reads on every request.
- Strengths: .htaccess allows applications (WordPress, Laravel) to manage their own rules without access to the main file. Ultra-numerous modules (mod_php, mod_rewrite, mod_ssl, mod_security). Compatible with almost all historical PHP applications.
- Weaknesses: under very high concurrent load (10k+ simultaneous connections), memory consumption becomes a handicap. Reading .htaccess on every request adds latency.
- Ideal for: multi-tenant shared hosting (each site has its .htaccess), traditional WordPress/Magento/Drupal applications, environments where per-site flexibility takes precedence over raw performance.