英语单词Capability, Competence, Capacity及 ability的区别

Ability 指的是与生俱来的能力。不需要后天培养或者训练。比如人类天生就有说话的能力。鸟类天生就有飞翔的能力。
Capability 指的是能完成某个特定需求的能力。当人们使用这个词的时候，说明人们关注的是对方知不知道具体如何去完成一个任务或实现既定的目标。
Capacity 指的是人们在指定的时间内能完成工作量的多少。比如生产线有capacity在一个小时内生产1000件成品。有时候有capability不意味着一定就有capacity。因为capacity侧重的是结果，但这个结果通常需要很多东西的协调一致才能实现。
Competence 强调的是一个人完成某件事的能力项。比如足够的业务知识，足够的手艺积累。这些能力不一定是先天就有的，完全可以是后天培养的。

英文解释应该能帮助大家更深的理解彼此的微妙差异。
Ability is the skill or competency to perform a task whether it is physical or mental. An ability is something that is inherent upon the genetic.
Capability means the ability to perform specific actions or achieve specific outcomes. Particularly in business it describes what an organization, unit, or team does. In considering whether a team has the capability to do something, we are really care whether they know how to do it, care if they understand the procedure.
Capacity describes the quantity of something. People cares if it is enough to achieve and complete something. In considering whether a team or a person has the capacity to do something, we are really care whether they can complete it within a limited period.
When discussing capacity, it is important to ask “How much do we have?” and the related questions, “How much is needed?” and “When do we need it?”
Having the capacity to deliver goods and services is more important than just having the capability.
Competence describes the quality or state of having sufficient knowledge, strength or skill to do something well enough. Competence is another word to describe skill. In considering whether a team or a person has the competence to do something, we are really care how effective they are, whether they have experience with the procedure or the sufficient training to use an equipment.
The following are examples from internet for you to better understand the subtle differences.
Bird has the ability to fly.
He has the capacity to run 100 meters in 18 seconds.
He has the capability to improve his capacity through training to 15 seconds.
As a runner I am incompetent, so I cannot compete successfully.
A runner may finish a marathon in 3 hours but may through training have the capability to complete a course in less than 2.5 hours.