1. Presidential Powers Executive Powers Enforcing laws
Leading federal bureaucracy
Issuing executive orders Appointing government officials
Removing officials
Executive privilege
A presidential executive order "is a directive issued to federal agencies, department heads, or other federal employees by the President of the United States under his statutory or constitutional powers," according to Robert Longley, writing at usgovinfo.about.com. "In many ways, presidential executive orders are similar to written orders, or instructions issued by the president of a corporation to its department heads or directors."
By contrast, a presidential executive action is kind of a catch-all term, writes NBC, which quoted an unnamed administration official in 2011 as saying: "It just means something the executive branch does. The use of any of a number of tools in the executive branch's toolbox."
Political writer Tom Murse says: "[Most] executive actions carry no legal weight. Those that do actually set policy can be invalidated by the courts or undone by legislation passed by Congress."
"What I'm going to be laying out is the things I can do with my lawful authority as president to make the system work better even as I continue to work with Congress and encourage them to get a bipartisan, comprehensive bill that can solve the entire problem," Obama said in a video posted Wednesday on the White House Facebook page.
Whether executive action or order, Republicans are not happy about the president's decision to go it alone on immigration.
In general, they say the issuance of any executive order represents a gross overstepping of presidential power. House Speaker John Boehner has even sued the White House over it. The Ohio Republican has accused Obama of using a "king-like authority at the expense of the American people and their elected legislators."
Of course, executive orders have been around since the first days of the republic. George Washington issued eight of them. Perhaps the most famous example was Abraham Lincoln's Emancipation Proclamation.
Critics say there's no specific Constitutional authority for them, but precedent has outweighed the critics.
Obama has actually issued far fewer executive orders than most of his predecessors, as Brookings scholar John Hudak, among others, has noted. As of last month, Obama had issued 193 directives classified as "executive orders" — the fewest of any two-term president since Theodore Roosevelt
Executive orders are as old as the U.S. Constitution itself and usually steeped in controversy.
Every president, from George Washington to Obama, has used them. More than 13,000, in one form or another, have been issued since 1789.
While there is no specific provision in the Constitution that permits them, there is a "grant of executive power" given in Article II of the Constitution,
(Read more: Frustrated Obama's message: I'll go it alone)
Presidents have used that language, along with their constitutional powers as commander and chief over the nation's military, to issue executive orders—whether it be to change domestic policy or go to war. And they are legally binding—the U.S. Supreme Court has upheld all but two legal challenges to them (see more on that below).
Most executive orders stem from a president's desire to bypass Congress. The legislative body is not required to approve any executive order, nor can it overturn an order. The best it can do if it doesn't like an executive order is to pass a law to cut funding for the order's implementation. But even then, the president can veto such a defunding law.

2. Legislative Powers State of the Union Address (goals for the year)
Submission of a budget
Proposing legislation
Submission of a yearly Economic Report
Signing and vetoing bills
Call special sessions of Congress

3. Diplomatic Powers Making treaties with foreign nations
Giving/removing diplomatic recognition
Appointing diplomats & ambassadors
Diplomat is an official representing a country abroad

4. Military Powers Commander in chief of the armed forces
Appoint and dismiss high-ranking military officials
“wage” war
Delegate money for weapons
Setup military governments in foreign lands
Declare an armistice
Use military to enforce US federal laws and restore order
Ultimate authority in military decisions

5. Judicial Powers Pardons for federal offenses
Reprieves (postponement of sentence) for federal offenses
Grants amnesty (applies to a group)
Appoints federal judges