Group of symmetries of a equilateral triangle

I was looking for the operation table for the symmetries of a equilateral triangle. I have found this webpage:
http://members.tripod.com/~dogschool/trianglegroup.html

  • e stand for the Do nothing movement.
  • a stand for the Rotate 120 degrees counterclockwise

    movement.

  • b stand for the Rotate 240 degrees counterclockwise
    movement.
  • X stand for the Flip about axis through the top vertex

    movement.

  • Y stand for the Flip about the axis through the lower-left
    vertex
    movement.
  • Z stand for the Flip about the axis through the lower-right
    vertex
    movement.
e a b X Y Z
e e a b X Y Z
a a b e Y Z X
b b e a Z X Y
X X Z Y e b a
Y Y X Z a e b
Z Z Y X b a e