What do you mean by 'collective responsibility'?

Collective responsibility means that the Council of Ministers is collectively responsible to the Lok Sabha. Since the policy of the Government is not that of one minister but of all the ministers, so if something goes wrong with the policy of only one minister, the whole Council of Ministers takes responsibility. A vote of no-confidence against one Minister is a vote against the whole ministry. Such a ministry having lost the confidence of the Lok Sabha has to resign.