Currently Being ModeratedFeb 13, 2013 9:45 AM (in response to little_Snoopy)
All new models of MB have flash (SSD) storage which, yes, are smaller capacity than hard drives - that's the way Apple is going with their lineup. SSDs are much faster and more reliable, but much more expensive byte-for-byte.
I don't know specifically what Mac you have, but with my 2010 Macbook Pro, when I switched out the HDD for a solid state drive, I removed the optical drive and put the hard drive back in there. So I have a fast boot drive, but store my music, photos and other large files on the HDD.
If you don't have that option, you have to find something external.