There really aren't "features" per se. You get an OS, and you can install whatever applications you want.
The base FreeBSD OS comes with a webserver, ftp server, ssh, MTA, etc all built right in as standard. You can choose to install any of the optional packages from the Ports system (over 10,000 to choose from last I saw) via either building from source (with the FreeBSD-specific patches included) or just install the binary package. The ports system contains all the same software you could install on Linux. You can even run Linux binaries on FreeBSD with it's binary emulation, which runs some Linux software even faster than it is on Linux itself!