The real-time information presented gives a good overview of the activity and status of the GC heap, but by collecting snapshots of the heap, very detailed information can be presented. A heap snapshot can optionally include the instance data of each instance on the heap, allowing the presentation of field values of instances. It is also possible to compare two snapshots, which is a very convenient and efficient way of detecting memory leaks in a program. A snapshot provides information about: all classes, all instances of classes, the call stacks of the instance allocations, the path to a root from each instance. If resource tracking is enabled, the snapshot contains additional information about unmanaged resources.