Person, People and Persons

According to Cambridge Dictionary of English Language, 

People is always used to refer to groups of human beings or humans in general. 

"I saw three people standing on the corner."

Persons is a very formal word. We only use it in rather legalistic contexts. 

"Any person or persons found in possession of illegal substances will be prosecuted". 

Person is used in singular to refer to any human being (a man, a woman or a child) 

"Joel is such a nice person."

It was the first great global event. The expedition of Fernando de Magallanes and Juan Sebastián Elcano left from Seville in 1519 and finiched in 1522 after circumnavigate the world. Spain is commemorating it with a programme of exhibitions, concerts, conferences and even a tour of various ports in a ship like the ones that first sailed around the world.

Link here and take a look to the great feat.