The core stats and examples of what the stats do.

STRENGTH: Physical ability, raw power. The higher the strength, the more a pony can carry. Earth Ponies tend to be stronger than Pegasi or Unicorns.

AGILITY: Physical ability, primarily speed. The higher the agility, the faster a pony can move. Pegasi tend to be more agile than Earth Ponies or Unicorns.

FORTITUDE: Both Physical and Psychological. The higher the fortitude, the more resilient a pony is (and a pony with high fortitude will be less likely to panic at the onset of a crisis)

CONFIDENCE: Both Physical and Psychological. The higher the confidence, the more successful a pony will be at their abilities (and a confident pony is less likely to panic as a crisis unfolds)

INTELLIGENCE: Psychological ability, primarily comprehension. The higher the intelligence, the smarter a pony is. Unicorns tend to be more Intelligent than Earth Ponies or Pegasi.

CUNNING: Psychological ability. The higher the cunning, the more "street smart" a pony is.

EXAMPLE:

Golden Plate (Earth Pony)

STRENGTH: Above Average

AGILITY: Average

FORTITUDE: Very High

CONFIDENCE: Below Average

INTELLIGENCE: Average

CUNNING: Below Average