Difference between cardinality=1 and FunctionalProperty?

Hi Folks,

Aren't the below two forms essentially stating the same thing:

     <owl:Class rdf:ID="Gun">
          <rdfs:subClassOf>
                <owl:Restriction>
                        <owl:onProperty rdf:resource="#serial"/>
                        <owl:cardinality>1</owl:cardinality>
                </owl:Restriction>
          </rdfs:subClassOf>
     </owl:Class>

     <owl:ObjectProperty rdf:ID="serial">
           <rdfs:domain rdf:resource="#Gun"/>
           <rdfs:range rdf:resource="&rdfs;#Literal"/>
     </owl:ObjectProperty>

VERSUS

     <owl:Class rdf:ID="Gun"/>

     <owl:FunctionalProperty rdf:ID="serial">
          <rdfs:domain rdf:resource="Gun" />
          <rdfs:range  rdf:resource="&rdfs;#Literal"/>
     </owl:FunctionalProperty>

Both forms state that an instance of Gun must have exactly one value for
the serial property; e.g.,

     <Gun rdf:ID="SmithWesson">
          <serial>ABCD</serial>
     </Gun>

Correct?  /Roger