Polygamy is a type of marriage in which a man gets married to more than one wife. The idea of practicing polygamy has been differently viewed by most religions. While some religions support it because they are free to do so, others do not support because it is against their beliefs. It is a generally known fact that, polygamy is very common in some parts of Africa, probably due to the fact that, it is the most common type of marriage in the past. A man can marry more than one wife so as to have more children.
And the idea behind it, is to have them so they can be helping him. In Islam, this type of marriage is acceptable. A man can get married to more than one wife at a time, as long as he is financially okay and he can cater for the varying needs of his wives. Christianity does not in any way support polygamy. The religion will advise you to get married to just one wife.