a CP is triggered whenever the Filesystem reaches a point where it wants to update the physical data on the disks, with whatever has accumulated in Cache (and was journaled in NVRAM).
a SnapShot is created whenever the snap-schedule is configured to trigger it or any other operation (SnapManager, SnapDrive, SnapMirror, SnapVault, Administrator) creates a new SnapShot. Creating a SnapShot also triggers a CP, because the SnapShot is ALWAYS a CONSISTENT IMAGE fo the Filesystem at this point in time.
You can access a SnapShot by many ways, e.g. mapping the network driveletter to a CIFS Share and then change into the ".snapshot" directory (or ~snapshot).
You cannot access a CP, because this is a process happening internaly in the filesystem.