Deployment Types - What are they really for?

Hello,

I am trying to find a description of what Deployment Types in SCCM 2012 actually do but for now I have one specific question about them.  

I am under the impression that I can create a 32bit and 64bit deployment type for a single application and use the priority setting in conjunction with requirments for each deployment to ensure 64bit OS machines receive the 64bit version and 32bit OS machine receive the 32bit version.  Is this correct?

Thanks,

Dustin