In DEB package, it is not possible to install an application in offline (in a computer which does not have any internet access). Because of the dependencies. In case of .snap, according to the OMG!Ubuntu, Snap packages can contain both application binary and any dependencies required for it to run.
Does it mean that, any .snap application can be installed in an offline pc (like the .dmg in MacOSX)? As there is no need to fetch any dependencies from the source.