A FreePBX system runs on dozens of software packages that are constantly being updated. Updates to these packages fix bugs in their operation, and often patch security holes that could otherwise leave the system vulnerable to attacks. As with any upgrade, make sure that a backup exists just in case the updates cause something to break.
Depending on the distribution that is used and the amount of maintenance time afforded for upgrades, the frequency with which the system is updated can vary widely. In general, it is more than enough to update the system once per week. A standard schedule would update system packages once per month.
Different Linux distributions use different methods for updating packages. As the installation guide in this book discussed setting up Asterisk and FreePBX under Ubuntu and CentOS, commands for updating these distributions will be shown here. Be sure that you check how to update your system if you use a different distribution.