The back 4 move the ball across the pitch (including the GK) looking to keep possession and find a forward pass to the 6.
After command from the coach (one whistle blow), possession switches to the attacking team, with the 6er now working as a central midfielder looking to combine with the 2 strikers and 2 wide players to keep possession.
The back 4 are compact working on communication, marking, covering and keeping balance.
On a second command from the coach (eg 2 whistle blows) the team in possession immediately attacks the opposite goal. The defending teams must transition to defend the oncoming attacking team.