MELEE: Used to be "strength". This represents a character's accuracy with hand-held weapons, physical ranged attacks (such as bullets or arrows) or physical disciplines such as martial arts or wrestling.
DODGE: Used to be "armor". This represents not how much of a beating you can take (armor) but how well you can avoid being grabbed, punched, or hit with short range weapons. The Evasion counter to Melee.
RANGED: Used to be "firepower". This represents marksman/sharpshooting accuracy with ranged or energy weaponry, usually guns.
SHIELD: This is the internal energy shields inside a Cybertronian's body that shunts off certain levels of ranged energy assaults. This counts as the 'evasion' to ranged/energy weapons, preventing damage to internal mechanisms. Missed ranged/energy attacks can be thought of as either not hitting, or not doing any damage (the shield absorbed it).
INITIATIVE: This is an accuracy stat for attacks that are based either on speed or surprise. High velocity attacks, sneak attacks, traps, surprises, or even quickdraw-type attacks use this stat.
REFLEXES: Used to be "sensors". This it the evasion counter to Initiative; it's how fast you can react to a surprise attack or a speed attack - or being able to see these attacks coming, either through being very observant, or having special sensors such as radar or sonar that see through obstacles.
MIND: Used to be "psyche". This represents the accuracy of attacks that disrupt or directly attack the mind of the victim, such as Cerebro shells or Mnemnosurgery -- or special odd outlier abilites, such as Tarn's spark-shattering voice, or Frenzy's hallucenation-inducing soundwaves.
WILLPOWER: Used to be "resolve". This is the evasion to Mind attacks either through sheer courage and determination, through having extra mental defenses, or unusual neural structure.
INTELLIGENCE: Not necessarily how smart someone is; this represents how quickly and correctly a character can solve complex problems. The higher the number, the more rapidly problems of extreme complexity can be solved.
TOP SPEED: Your best speed in your fastest altmode. 6 and up is the minimum requirement for flight speeds; 9 and higher is needed for space flight.
LEADERSHIP: How well your character can convince others to follow their commands/suggestions - which can be done in MULTIPLE ways. Everything from natural charisma to intimidation to manipulation.
SKILL: This represents the general level of proficiency in your character's stated function.