Mastering WP-CLI: A Complete Guide for Intermediate WordPress Developers
Install plugins, update themes, manage users and run database tasks from the terminal in seconds, instead of clicking through the admin.
WordPress guides.
Security, WP-CLI and running a WordPress site well.
Common WordPress Security Mistakes and How to Avoid Them
WordPress itself is secure. Most problems come from avoidable mistakes: here are the common ones, and how to avoid them.