Lifeform

A lifeform or life-energy force is any distinct entity which is generally considered to exhibit signs of "life." The fact of whether or not something was considered a lifeform leads to many topics of hot debate.

Not every criteria defining "life" can be used in defining lifeforms. Since exploration has expanded into some of the more deeper parts of the universe, there have been discoveries of different kinds of life besides organic.
There have been documented cases of inorganic life (crystalline life), artificial life (androids), and non-corporeal entities (Q beings) have all been considered lifeforms by the Federation.

When using starship sensors and medical or scientific tricorders, one could detect organic lifeforms by localizing blood flow (and blood type, if using a medical scanner), heart rate, or heat signatures.