His cabinet and several advisors chosen by him for specific advice
(in the US) By the President (hopefully) with the consultation of his advisors.
There are different types of advisors for specific subjects. These advisors are experts and often practitioners in the same field. Some examples of advisors are financial advisors, insurance advisors, health care advisors and medical advisors.
Greenfield Advisors was created in 1976.
Aurum Advisors was created in 2004.
BMR Advisors was created in 2004.
RCP Advisors was created in 2001.
RCP Advisors's population is 26.
Amaranth Advisors was created in 2000.
Sagent Advisors was created in 2004.
The population of Sagent Advisors is 110.
Dimensional Fund Advisors's population is 500.