Casque vs. heaume
The French words casque and heaume both refer to types of helmets, but they differ in their historical context and usage.
Casque
A2Casque is a general term for helmet, used in modern French to describe various types of protective headgear.
Les motocyclistes doivent porter un casque pour leur sécurité.
(Motorcyclists must wear a helmet for their safety.)
Les pompiers portent un casque spécial pour se protéger des débris.
(Firefighters wear a special helmet to protect themselves from debris.)
Le casque de vélo est obligatoire pour les enfants.
(Bicycle helmets are mandatory for children.)
Heaume
B2Heaume specifically refers to a medieval helmet, typically worn by knights and covering the entire head.
Le chevalier portait un heaume orné de plumes.
(The knight wore a helmet adorned with feathers.)
Le heaume du roi était fait d'or et d'argent.
(The king's helmet was made of gold and silver.)
Dans les musées, on peut voir des heaumes datant du Moyen Âge.
(In museums, you can see helmets dating back to the Middle Ages.)
Summary
While casque is a versatile term for modern helmets used in various contexts, heaume is specifically associated with medieval armor and is rarely used in contemporary French except in historical contexts.