Group Chat is Whatsapp lets your create a group, add and invite your contacts as participants and start chatting with them. On Whasapp for Android phones and tablets, you need to do as follows to create a new group:
1. Open "Whatsapp"
2. Press Menu Button and select "New Group"
3. Type a name as the group name, and add an optional group icon
4. Type contact name to add group participants (You can add up to 50 contacts in the group)
5. Once done, tap "Create"