Basic QoS question

Hi there,

Just one question which I consider it is a basic QoS question. What's the difference between using traffic policing or using class-based traffic policing? For example:

Traffic Policing

 qos car inbound acl 3001 cir 1000 green pass red discard

Class-Based Traffic Policing

traffic classifier class1

 if-match acl 3001

traffic behavior beh1

 car cir 1000 green pass red discard

traffic policy traff1

 classifier class1 behavior beh1  

interface Ethernet0/0/0

 traffic-policy traff1 inbound

What's the difference? The same result can be achieved by using the two types of traffic policing... The same for traffic shaping for instance...

Thanks in advance,

Julián