The difference between a "Skill Floor" and a "Skill Ceiling"

I often hear the terms skill floor and skill ceiling thrown around interchangeably. I think it's important to note the difference between the two.

Simply put: A skill floor is the minimum level of ability required to be effective with a hero. A skill ceiling is the level of skill required to use a hero to their maximum potential.

Skill floor is very easy to determine for most heroes. Soldier, Reaper, Mercy, and D.Va are all heroes with generally easy abilities to learn and use in combat. The average player can use all of these heroes effectively. They have low skill floors.

Other heroes, such as Zarya, Ana, or Widowmaker, are more difficult to use effectively in a match. Learning to secure kills with Widowmaker is much more difficult than learning to do so with Soldier or Reaper. Healing with Mercy will also be inevitably easier than with Ana simply due to the nature of their kits. These are higher skill floor heroes.

Skill ceiling is a different story. This is the set of skills, techs, and knowledge it takes to truly master a hero. The skill ceilings for each hero are much harder to determine, since each hero has such different abilities and functions it's impossible to compare them all objectively.