U.S. Army First Lieutenant Kirsten Griest (C) and fellow soldiers train for combat at Fort Benning, Georgia, Apr. 20, 2015. Reuters

Veterans Day, formerly known as Armistice Day, traces its origins back to World War I. Though the war officially ended Jun. 28, 1919 with the signing of the Treaty of Versaille, fighting actually stopped months before, on Nov. 11, 1918 when Germany and the Allied forces declared an armistice, or a truce. From that moment on, Nov. 11 became a day to recognize those serving in the armed forces. This Friday, the nation will honor veterans both living and dead on its 78th official Veterans Day.

Congress passed a resolution in 1929 designating Nov. 11 as a day to commemorate the end of the World War I. "Whereas it is fitting that the recurring anniversary of this date should be commemorated with thanksgiving and prayer and exercises designed to perpetuate peace through goodwill and mutual understanding between nations," the resolution stated.

Armistice Day didn't become an official holiday, however, until more than 20 years after World War I ended, when it was declared a federal holiday in 1938. In 1958, President Dwight D. Eisenhower changed the name of the holiday to Veterans Day.

"In order to insure proper and widespread observance of this anniversary, all veterans, all veterans' organizations and the entire citizenry will wish to join hands in the common purpose," Eisenhower's proclamation read.

The word veteran refers to any person who has served or is currently serving in the armed forces. As of 2014, there were 19.3 million veterans in the United States, 1.6 million of whom were females and seven million of whom had served in the Vietnam War.

Not to be confused with Memorial Day, Veterans Day is a day to recognize the service of both the living and the dead who served in the nation's armed forces. Memorial Day is set aside to commemorate only those veterans who lost their lives.

There are various ways to show support for veterans Friday. We Honor Veterans, a national group that cares for those who served, encourages people to first and foremost set time aside to spend with a veteran so he or she can share their story. Attending a Veterans Day event, visiting the grave of a service member and hanging a flag outside your home are also good ways to commemorate those who have served. The Veterans History Project, a program aimed at telling veterans' stories, urges anybody to participate by interviewing a veteran, sharing their own story or donating a veteran's collection of items.