what is a host family?Some English introduction about it please.

A Host Family acts as the International Student’s family while they are in the foreign countries attending School.This family,who most likely will already be a part of the school community,will accept this student into their home as one of their own children.The International Student will participate in family events,such as attending church on a weekly basis,going along on family outings,and enjoying the holidays with their host family.The Host Parents will hold the International Student accountable for homework,household chores,and other routine family obligations and will discipline the student when necessary.This nurturing environment helps each student with the transition from one country to another.i've learnd some of host families just invite international students to attend many activities with their families, not accepting them into their home as their own children.Therefore, i just wanna know whether the international students will live in those families, or just the students become close members to those families. thanks~generally speaking, students live with these families.