Columbia, SC (WLTX) - In his first 28 days President Donald Trump has signed 12 executive orders. That may seem like a lot, but compared to previous presidents it's average.

President Barack Obama signed 14 in his first 28 days, while President George W. Bush signed three and President Bill Clinton signed six.

An executive order is an order signed by the president or a government agency (like the executive branch of a state) and must be obeyed like a law.

"One of the interesting things about executive orders is that they are not explicitly described in the constitution, but they have been there since the beginning," says USC Political Science professor Charles Finocchiaro.

The first executive order was singed by George Washington in 1789.

"It's really typical in the first few days for the president to issue a few," says Finocchiaro. "These are really symbolic or ping pong issues where you want to undue what the other party in power did."

There is no limit for how many executive orders can be signed by a president. Franklin D. Roosevelt signed 3,721 executive orders in his 12 years as president. That's the most for any president.

No one has come even close to that number. In recent years President George W. Bush signed 291 in his two terms, while President Obama signed 276.

President Trump is just getting started and explained to reporters, in a press conference on Thursday, that more executive orders dealing with national security and immigration are forthcoming.

For a look at recent executive orders signed by President Trump, click on the link here.