Question:  'What is the difference between "someone" and "somebody" ?'

Answer: There is no difference. They mean exactly the same thing.

Ahi te va tu respuesta, espero que te sirva de algo: http://ingles.about.com/od/Palabras-confusas/tp/Palabras-que-empiezan-con-some-como-something-someone.htm

Somebody and someone are used interchangably.  I tend to use somebody when I want to visualize some person physically .... :P ... , and I tend to use someone when I'd rather not want to visualize some person physically. ... :( ...

"Someone" and "somebody" can be used interchangably. "Someone” may be used in more formal situations, however this is not something the majority of people do in everyday speech.

There really isn't much of a difference between the two. I tend to use both interchangably.