If you use Vim for programming, you find that by default based on the type of the file, Vim enables syntax highlighting. That is if your file name is myfile.c or myfile.C, Vim enables Syntax highlighting for the C language. Likewise, it enables syntax highlighting for a large number of well known (programming) languages. If you are wondering where you can find these syntax highlighting files, you can check the following directory.
Currently in my system, it is located in the following directory
Let’s check the directory contents
$ ls /usr/share/vim/vim73/syntax ... config.vim idl.vim plp.vim tf.vim conf.vim indent.vim plsql.vim tidy.vim context.vim inform.vim pod.vim tilde.vim cpp.vim initex.vim postscr.vim tli.vim crm.vim initng.vim po.vim tpp.vim crontab.vim inittab.vim povini.vim trasys.vim ....
Thus for every programming language, they have an associated .vim file. For C++, there is cpp.vim. For crontab entries (/etc/cron.d), there is crontab.vim
Since, I am using Vim 7.3, the above syntax files are located in the vim73. But if you are looking for future versions, you can run the following command to get the location
$ find /usr/share/vim/ -iname "*syntax" /usr/share/vim/vim73/syntax