They are one in the same. BDCP is the commissioning source. SNA, NFO, Supply, Crypto, Intel, etc are all communities within the Navy that you can be recruited for through BDCP. A pro-rec for any of those indicates that the Navy wants you for that specfic community. As it was said before, receiving a pro-rec is the hardest part. However, receiving a pro-rec does not guarantee final selection into the community. If you get non-select for some reason (I almost blew it on the EPSQ), you will have to start the whole process again. Do not pass go, do not collect your BDCP money, etc etc....
Bottom line - you're not in until you sign on the dotted line, and that doesn't happen until after your findocs have been APPROVED