The content below is entirely editable.
A spark is basically the soul of a Transformer, it is what truly separates them from normal robots.
Types of Sparks:
Spark: The basic kind most Transformers have
Dark Spark: A rare mutation that causes malevolent behavior in the Transformers who have one, this is not a common occurance, even most Decepticons don't have Dark Sparks... And some believe the sadistic behavior of the Autobot Blades may indicate he has one. The Decepticon Skyquake has one, and the Spark of Jazz was once corrupted and turned into a dark spark.
Immortal Spark: Only Starscream is known to have one, though the Maximal/Predacon version of Rampage has an "artificial" immortal spark.
Reincarnated Spark: A spark that was once part of a now deceased Transformer reincarnated into the body of a living one. An example of this is the Maximal named Leo Prime who is the reincarnation of the Autobot leader Optimus Prime.
Sparkless: A sparkless Transformer is a very rare occurance, they are generally the result of being resurrected by Dark Energon, but some others have simply always been sparkless, such as Cruellock.
All sparks in someway or another stem from the Allspark which was created by Primus and granted the first Autobots and Decepticons life.