A Warrior without a King
A professional takes the time she needs to acquire the necessary knowledge for her craft.
A professional applies the knowledge, through practice (many iterations), to build up the skills.
A professional combines various, relevant skills and tools to form an ability or capability.
Capabilities can turn into products or services that other may choose to pay for.
When an opportunity strikes, a professional can assess the end state and quickly draw from her inventory of capabilities, skills, and tools to achieve the desired results.
When the opportunity or situation is complicated, amateurs quickly run out of options.
A professional can assess the problem in a way that the amateur flees from.