The council of ministers are collectively responsible to the Parliament. It means that when the cabinet or council of ministers have reached a decision, all the ministers must defend it inside the Parliament.
If any law or policy is rejected by the Lok Sabha or decision or budget proposal made by the ministry, it is taken to be a no confidence against the entire council of ministers. The passing of no confidence leads to the resignation of the entire council of ministers.
Apart from this, if the no confidence is passed against the Prime Minister, then also it leads to the removal of the entire council of ministers. The reason behind this is
the Prime Minister is the leader of the council of minister. Hence, the collective responsibility has its own importance.