Actually all files are in binary format. There is nothing else.
But I suggest you not to store the file in the database itself. It can grow really large, and in most cases you will gain nothing with it. There is a feature of Sql Server called
FILESTREAM[
^]. It has little to do directly with the filestreams from .net for example. This feature enables you to have all pros of of storing files in the database, and the files you store are really managed by sql server (you have backup and so on), but they are not stored inside the database, but on the filesystem. And you have several ways to access them, there is even a share you can use if you want remote access. The major advantage of it is that you don't need to put the huge load on the sql server that arises during such operations.
Of course, you have means to deal with them from c# too.
Please see following articles:
How Do I: Use SQL File Stream[
^]
http://blogs.microsoft.co.il/blogs/bursteg/archive/2008/05/12/ado-net-entity-framework-support-filestream.aspx[
^]
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