Functionality and Capability

noun

• Capable of serving a purpose well.
  • usage: "software with greater functionality"

noun

• The quality of being capable - physically or intellectually or legally.
  • usage: "he worked to the limits of his capability"
  • synonyms: capableness
• The susceptibility of something to a particular treatment.
  • usage: "the capability of a metal to be fused"
  • synonyms: capacity
• An aptitude that may be developed.
  • synonyms: capableness, potentiality

• (n.) Capacity of being used or improved.
• (n.) The quality of being capable; capacity; capableness; especially intellectual power or ability.

(DoD) The ability to execute a specified course of action. (A capability may or may not be accompanied by an intention.)