How much code is in a .bin file?

I have just compiled to a .bin file in Dynamic C and the file size is 283,006 bytes.
When I program the same code into a target through Dynamic C is says it is sending a total of 246,144 bytes.

Is the code size only 246,144 bytes?

I am interested to know what ‘type’ of bin file Dynamic C creates, and how the file is made up.