The cease-fire that ended the Vietnam War resulted in many American troops being withdrawn from Vietnam and American POWs being released.
The Vietnam War was a very difficult war for the United States. President Lyndon Johnson limited many troops in what they could do, so it was very hard to get ahead. The jungles of Vietnam were also very hard to fight in and it was almost impossible to locate enemies.
After all of this went on for awhile, Richard Nixon became president and realized that the United States fighting in this war was essentially going nowhere. He decided to pull American troops out of Vietnam and a few years later settled a cease-fire that officially ended the Vietnam War.
The United States had ended up losing the Vietnam War and now Vietnam was known as a communist country.