Homesickness is a feeling of unhappiness a person may have when away from home or from familiar surroundings or people. It has a similar meaning to the word nostalgia.
Homesickness is not about how much you miss your home. It is about how much dependent you are on other people or your parents, how much pampered you are or how much difficult it is for you to be in a different place. People sometimes become homesick when they travel. They miss their own home and desperately want to go back. Children may often feel homesick, especially when they are away from their parents for the first time. Usually these feelings will go away as one gets used to the new environment, but sometimes homesickness can make a person depressed.
People may easily feel homesick if they travel to an environment in which the culture is very difficult to what they are used to, and especially if a foreign language is being spoken. Children who are sent away to boarding school will very often feel homesick.
A good way to help children overcome (or avoid) homesickness is to start with being away from home just for short periods, staying with people they know well, e.g. grandparents or good friends.