When a player controls and maneuvers the puck with their hockey stick. It's usually carried out by players on the attack, but it can also be used as a defensive move to get out of trouble.
When a player has possession of the puck and carries it up or across the ice or outmaneuvers an opponent while keeping possession of the puck they are stickhandling. However, while it's more difficult to do, it can also be performed when standing still as a way to beat an opponent while maintaining possession of the puck. It's usually associated with offense since players stickhandle around their opponents in the neutral or offensive zone to create scoring chances and to set up their teammates. It can also be used in the defensive zone when an attacking player attempts to carry the puck out of their own zone. It's not commonly used as a defensive tactic, but sometimes a defenseman will be able to stickhandle their way out of an opponent's reach and then move the puck out of harm's way and to a safer position in the defensive zone.