In surfing, skateboarding, snowboarding and aggressive inline skating, frontside and backside are terms that are used to describe how a person approaches an obstacle or performs a certain trick.
The only exception to this rule is fakie as there is an implied 180 degree rotation already completed causing the expression to be reversed.
For a rider traveling in the "regular" stance (left foot leading), frontside means to rotate counter clockwise (as seen from above).
To carry out a frontside boardslide, a regular-stance skater will rotate slightly clockwise before sliding, facing away from the direction of travel.
In Aggressive Inline Skating, frontside and backside are used to describe the way the skater's feet are positioned when grinding on an object.