The SnapShot operator is used to create a mesh snapshot out of a group of particles. Out of many particles (source) one particle is created that represents the mesh at that time along with all the masses added up.
It is best to control the snap shot through the ON input.

ON - (Bool) This input data stream determines whether the operator is considered 'on' or 'off'. You can connect other operators to this input channel such as a Bool Helper to activate/deactivate the whole operator.

Time - (Time) This input data stream is used to define the local time for the operator when the user wants to override the default system time.

Particle A - Individual particles may also be input for Snapshot along with Particle B; a combination of particle pairs is possible.

Particle B -  Individual particles may also be input for Snapshot along with Particle B; a combination of particle pairs is possible.

Born Particle - (Particle) This output data stream sends particle data for newly created particles to other operators. Every particle birth will activate all rules connected to this particle data stream. As a result , this can be used to directly assign a value to the particle.

Source - select the source particle group that will be used to snap shot the mesh data from. Subgroups will be ignored.

Include Sub Groups - check this option to include the Sub-Group particle hierarchy.

Kill Source Particles - checked by default, this option removes by default the snap shot particles. To keep the original particles and mesh uncheck this option. Be careful! When this option is turned off many continuous snapshots can be created.

Merge To First (A) - when checked, this option allows merging with the first particle connected to Particle input port A. If particles are fed into Particle Port B, they will be merged and added to Particle A instead of creating a new particle.

Target - selects the target particle group where the one mesh particle lands.