There are several types of extractions.  Fluid extraction is when there is an entity that is fluid residing within the physical body of the client.  It is an unwanted energy that has lodged itself in the clients body and resides within and shows up as a tricky fluid energy moving within the body.  A solid extraction shows up as an imprit or solid energy which appears in the luminous energy field, residing outside of the physical body.  Both types of energies are intrusive, and cause unneccessary discomfort, often they instigate the client to behave in uncharacteristic ways or have uncharacteristic pain.