system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Executive Privilege

I've been hearing the media talk about 'Executive Privilege' in-regards to Presidents of United States testifying and answering questions in court?

I'm from outside the U.S. so I have no knowledge of what it means.
gpt
"Executive privilege" refers to the notion that the President of the United States (and by extension certain other members of the Executive Branch) doesn't necessarily have to respond to subpoenas issued by the courts or Congress. There are two basic kinds of executive privilege: deliberative and communications.

"Deliberative privilege" or "deliberative process privilege" protects the President, and potentially *any* executive-branch decision-maker from having to divulge information about the process by which certain important decisions are made. The idea is that in order to make fully-informed decisions, the the President and executive agencies need to be able to fully hash things out. Brainstorming, basically. Brainstorming invariably involves people floating ideas that turn out to be *bad* ideas. Sometimes it involves suggesting courses of action or relying upon sources of information that, in hindsight, are improper. But that's an essential part of the process in identifying *good* decisions, so the US legal system exempts certain materials related to "deliberative processes" from disclosure. 

"Communications privilege" protects the President from having to divulge communications that he himself conducts with his immediate advisors: cabinet-level officials, immediate aides, White House Counsel, etc. This is viewed as being inherent in the separation of powers which is a fundamental feature of the form of government created by the US Constitution. If Congress or the Courts could force the President or his immediate advisors to disclose all of their communications, it would be practically impossible for the President to do his job. This is privilege is much, much harder to overcome than deliberative process privilege.