Each port's Makefile automatically fetches the application source code, either from a local disk, CD-ROM or via -ftp, +ftp, unpacks it on your system, applies the patches, and compiles. If all went well, a simple make install will install the application and register it with the package system.
For most ports, a precompiled package also exists, saving -the user the work of having to compile anything at all. Each port -contains a link to its corresponding package and you may either simply -download that file and then run the -pkg_add -command -on it or you can simply grab the link location and hand it straight -to pkg_add since it is capable of accepting FTP URLs as -well as filenames.
+the user the work and time of having to compile anything at all. Use +pkg +install to securely download and install the precompiled +version of a port. For more information see Using +pkg for Binary Package Management