Different criteria and the individual differences:

User awareness :

NOS: Users are aware of multiplicity of machines.

DOS: Users are not aware of multiplicity of machines.

Resource Access:

NOS: Access to resources of various machines is done explicitly by remote logging into the appropriate remote machine or transferring data from remote machines to local machines, via the File Transfer Protocol (FTP) mechanism.

DOS: Access to remote resources similar to access to local resources.

Computation and Data Migration:

NOS: transfer the the data, to and from the remote server and only the server performs the all or most of the computation.

DOS: transfer the computation, rather than the data, across the system.

Process Migration:

NOS: execute an entire process, or parts of it, at the remote server. DOS: execute an entire process, or parts of it, at different sites.

Data Access:

NOS: run process remotely, and needs to transfer all the data to the server for processing.

DOS: run process remotely, rather than transfer all data locally.

Architecture Model:

NOS: Employs a client-server model

DOS: Employs a master-slave model.