2 Answers

All three could be known as "chargers", but they were distinct types for different purposes.

The one we think of first is the destrier, the heavy warhorse. This would be almost the equivalent of a tank, a very strong and highly-trained horse the knight could ride into battles and jousts.

They were usually stallions, as they could put on a vast amount of muscle as they grew, and could support a knight in full armour. Although they were heavy horses, they weren't particularly tall: an average would be around 15 hands, unlike modern shire horses, standing over 18 hands. Despite their weight, they had to be nimble and able to react quickly. Their value came from their training, rather than sheer size.

Destriers were actually not very common, as they were hugely expensive. They were probably most useful in jousts.

The second type is the courser, which was far more common. They were much lighter and faster, so maybe more useful for battle. They weren't exclusively stallions.

Although they would also need extensive training, they were less expensive than the destrier. Coursers would be ridden by knights and his men-at-arms.

The third type was the rouncy. This was the most common type of horse, an all-purpose beast for use in battle by the men-at-arms, and even as a pack horse. They were the least expensive type.

Another expensive type, almost the "sports car" model, was the palfrey. They were highly-bred, very expensive horses with a distinctive smooth gate, like the Icelandic tölt. They were preferred by the men and ladies of the court for hunting and ceremonial use, where they could show off their expensive horse.

White Arabic Stallions