difference between capability and ability.
I know the difference between the two words when we talking about people or animals .
capability refers to the future potential

but I don't know the difference when we talk about ''things''.
for example:

The system has the ability to run more than one program at the same time.
VS: The system has the capability to run more than one program at the same time.

so what is the difference when we talk about ''things''.

thank you very much .
a new train capable of reaching very high speeds

VS : a new train able to reach very high speeds

Question

difference between capability and ability. 
 I know the difference between the two words when we talking about people or animals .
capability  refers  to the future potential

but I don't know  the difference when we talk about  ''things''. 
for example:

The system has the ability to run more than one program at the same time. 
VS:  The system has the capability to run more than  one program at the same time.

so what is the difference when we talk about ''things''.

thank you very much . 
a new train capable of reaching very high speeds

VS : a new train able to reach very high speeds

Answer

'Capability' = one's maximum ability, to one's limits of capacity for doing/accomplishing something;

On the other hand, ability is more applicable to the generic, non-quantifiable quality of being able to do something/capable of doing something

'Ability' is closer to a talent, a natural skill which is hard to quantify, whereas capability is more applicable to enterprises, rather than persons, or, if it is applied to a person, it may more often reflect on limitations, rather than talents.

Examples:

1. Her ex-husband's capability to pay alimony does not extend to supporting her drug habit.

2. His ability to listen attracts many who want to cry on his shoulder.