Current releases are 8.2 and 7.4. See the release pages.

A FreeBSD system is composed of:

• The base system, consisting of the kernel plus world (the OS files in /usr/src), updated with csup.
• User installed applications, which are handled via the ports tree, see /var/db/pkg/*, updated by compiling ports or installing binary packages.

1. Run portsnap to sync the ports tree

portsnap fetch 
portsnap extract (only first time)
portsnap update

2. Run portsdb to update INDEX.db.

- check for vulnerabilities:

portaudit -Fda 

- update INDEX.db (use -Uu to create de DB and -fu to recreate it if corrupted)

portsdb -Fu

3. Use portversion to determine which applications need upgrading.

portversion -l "< "

4. Use portupgrade to upgrade those applications:

- upgrade all with dependencies using interactive mode:

portupgrade -arRi

- with logfile

portupgrade -rR ruby-shim-ruby18 -l logfile

These precompiled packages are separated into categories by the architectures for which they are available. Packages are further separated into several “release” directories, one for each current production release built from the ports collection and shipped with the release. These production release directories are never updated. There are also stable and current directories for several major release branches. These are updated more or less weekly. In most cases a package created for an older version of FreeBSD can be installed and used on a newer system without difficulty since binary backward compatibility across major releases is enabled by default.

pkg_add -r <paket>
pkg_deinstall paket* or pkg_delete paket

- list of installed packages

pkg_info

- list outdated ports

pkg_version -v

- list unused ports

pkg_cutleaves

- find out to which port an application belongs

pkg_which pkgdb
pkg_which -v kde*

freebsd-update provides binary upgrades to the FreeBSD base system. It only works on RELEASE systems with a GENERIC kernel, and provides two separate functions:

1. it allows for binary security and errata updates to be applied to the FreeBSD base system without the build and install requirements.

freebsd-update fetch
freebsd-update install

2. the utility supports minor and major release upgrades.

freebsd-update -r 8.2-RELEASE upgrade

pkg_add -r is the binary method, but if the latest version is no available in the default RELEASE mirror, the variable PACKAGESITE should be changed to STABLE as packages-*-release directories are built from the ports collection shipped with the release, and are not updated. But packages-*-stable and packages-*-current are updated roughly once a week. To make this the default, change /usr/local/etc/pkgtools.conf:

setenv PACKAGESITE ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/packages-6-stable/Lat...

- upgrade port tree using portsnap:

portsnap fetch
portsnap update

- then update ports db and check if the installed packages and ports are older than the new port tree:

portsdb -Fu
portversion -v -l"<"

- if there is anything to upgrade you should make sure that PACKAGESITE is using STABLE instead of RELEASE and then run portupgrade:

portupgrade -vaRrp

To avoid breaking software you should always check /usr/ports/UPDATING