FreeBSD is bundled with a rich collection of system tools as part of the base system. In addition, FreeBSD provides two complementary technologies for installing third-party software:
the FreeBSD Ports Collection, for installing from source
packages, for installing from pre-built binaries.
Either method may be used to install software from local media or from the network.
For more detailed information you can refer to Chapter 4. Installing Applications: Packages and Ports
While the two technologies are similar, packages and ports each have their own strengths. You should select the technology that meets your requirements for installing a particular application.
My policy is to use pre-compiled binaries as much as possible to:
avoid the need of tinkering with foreign source code and compiler options
have easily reproducible build
update more easily
use more reliable and stable versions.
A compressed package tarball is typically smaller than the compressed tarball containing the source code for the application.
Packages do not require compilation time. For large applications, such as Mozilla, KDE, or GNOME, this can be important on a slow system.
Packages do not require any understanding of the process involved in compiling software on FreeBSD.
Packages are normally compiled with conservative options because they have to run on the maximum number of systems. By compiling from the port, one can change the compilation options.
Some applications have compile-time options relating to which features are installed. For example, Apache can be configured with a wide variety of different built-in options.
In some cases, multiple packages will exist for the same application to specify certain settings. For example, Ghostscript is available as a ghostscript package and a ghostscript-nox11 package, depending on whether or not Xorg is installed. Creating multiple packages rapidly becomes impossible if an application has more than one or two different compile-time options.
The licensing conditions of some software forbid binary distribution. Such software must be distributed as source code which must be compiled by the end-user.
Some people do not trust binary distributions or prefer to read through source code in order to look for potential problems.
Source code is needed in order to apply custom patches.