An independent executive agency is an organization that functions outside of direct presidential control. An example of an independent executive agency would be the Federal Communication Commission.
Independent executive agencies oversee important federal government tasks. Unlike the executive departments, these organizations are self-governed and do not answer to the executive branch.
Although the organization does not answer to the president, the president is responsible for appointing the department heads of the executive agencies. However, unlike executive department heads who can be removed based on political ties, heads of independent executive agencies can be removed only with sufficient cause.
Moreover, independent executive agencies operate similarly to the government with a tripartite structure to create regulations, handle conflicts and prosecute violators of the instituted regulations.
Independent executive agencies form when acts of Congress that require an organized body to perform functions of the government. Congress often will create these agencies when the actions required extend beyond the means of regular legislation. For example, the CIA is responsible for collecting and analyzing information in order to protect national security. The CIA independently operates, but must remain with the scope of legislation, or enabling acts passed by Congress that detail what the agency can and cannot do.