01 / FREEBSD
Base System
FreeBSD is a complete Unix-like operating system developed as an integrated project, with the kernel, userland, libraries, utilities and documentation maintained as part of a coherent base system. This separation between the base system and third-party software gives administrators a predictable foundation for building servers and infrastructure. The system also provides facilities such as sysctl, devfs, geom and a well-defined configuration hierarchy for controlling hardware, networking, storage and kernel behaviour.
02 / FREEBSD
rc.d
FreeBSD uses the rc.d system to initialize the operating system and manage services during boot and shutdown. Configuration is primarily controlled through /etc/rc.conf and related files, while individual service scripts in /etc/rc.d and /usr/local/etc/rc.d define how daemons are started, stopped and monitored. The framework uses dependencies and standardized service interfaces, providing a straightforward mechanism for controlling system services without requiring a separate service manager such as systemd.
03 / FREEBSD
Jails
FreeBSD Jails provide operating-system-level isolation by restricting processes to a controlled filesystem, process namespace, network configuration and set of resources. Unlike full virtual machines, multiple jails share the host kernel while maintaining separate user-space environments. Jails can therefore provide lightweight isolation for services, development environments and hosting workloads, with mechanisms such as VNET, resource controls and hierarchical jails extending their isolation and networking capabilities.
04 / FREEBSD
ZFS
ZFS is an advanced filesystem and storage management system integrated into FreeBSD. It combines filesystem and volume-management functionality, providing pooled storage, checksumming, snapshots, clones, compression, replication and software RAID through RAID-Z. ZFS uses copy-on-write semantics and maintains checksums for stored data and metadata, allowing corruption to be detected and, where redundancy exists, automatically repaired. Its storage-pool architecture also allows capacity to be managed independently of traditional disk partitions.
05 / FREEBSD
PF
PF, or Packet Filter, is a stateful firewall and packet-filtering system available in FreeBSD. Rules can control traffic based on addresses, networks, protocols, ports and connection state, while features such as NAT, tables, traffic normalization and traffic shaping provide additional network-control capabilities. PF configuration is commonly maintained in /etc/pf.conf, and administrators can inspect and manipulate the active ruleset using tools such as pfctl.
06 / FREEBSD
Networking
FreeBSD provides a mature networking stack supporting IPv4, IPv6, routing, VLANs, bridging, link aggregation, wireless networking, tunnelling and advanced network interfaces. Network configuration is commonly managed through rc.conf, while commands such as ifconfig, route, netstat and sockstat provide visibility into interfaces, routes and network sockets. FreeBSD networking also integrates closely with Jails, allowing isolated workloads to have independent network identities and configurations.
07 / FREEBSD
Ports
The FreeBSD Ports Collection provides a framework for building third-party software from source using standardized build definitions known as ports. Each port describes how software is obtained, configured, patched, compiled and installed while integrating with FreeBSD's filesystem and packaging conventions. Ports provide fine-grained control over build options and dependencies, making the system particularly useful when software needs to be compiled with specific features or configuration choices.
08 / FREEBSD
pkg
pkg is FreeBSD's package management system, designed to simplify the installation, updating and removal of software packages. It handles dependencies, verifies integrity and maintains a database of installed packages. Administrators can use pkg commands to search for packages, install them from repositories, update the system or remove unused software.