Chico, muchacho, niño and their female equivalents chica, muchacha and niña - these words are used in Spanish to refer to children. But they are used in colloquial speech in different ways.
The use of chico ("chico") and chica ("chica")
As a general adjective, "chico" is used in the meaning of "small" in those cases when it comes to the smallest in height or size compared to others. However, when using this word as a noun referring to people, it usually means the youngest in age, and not in height. The age of children for whom the words “chico” and “chika” are used differs slightly in different regions.
The use of muchacho ("tormentor") and muchacha ("torchach")
"Muchachos" is the plural of the word "muchacho." When it comes to teens, this word is usually used instead of "chico." Translated from Spanish, “Muchachos” means “boys” or “boys”. In addition, sometimes this word can be used when it comes to young men. However, it is used more in colloquial speech. This appeal is not used in relation to strangers.
In Colombia, for example, “torchachos” is a concept that is almost exclusively used to refer to young people or adolescents. And it never applies to young children.
In the Philippines, “tormentor” has a slightly different meaning. Here it is used as a servant designation.
The use of niño ("nino") and niña ("ninya")
“Nino” and “Ninya” are more general and sometimes slightly more formal words for children. Their use may be preferable in situations where it is a question of a child in general, and not of a specific boy or girl. "Nino" is also used in situations where the young age or inexperience of a person is meant.
In most cases, you can use any of the above words to refer to boys and girls. However, it is worth understanding the difference between these words and using them depending on the context and situation.