The first molecule is cinnamyl chloride and has the structure
where the phenyl group appears.
The reason why phenyl is described as a substitutent is that there is no naming rule which encompasses both aliphatic chains and rings. So chains and rings are considered separately and are substituent of each other. If the highest priority moiety is on a ring, the ring becomes the parent chain. If it is on a chain, like in your case, the chain becomes the parent hydride and the phenyl group is considered a substituent.