7th District Council Election held in Hong Kong

Elections for members of grassroot consultative organizations known as District Councils were held on December 10 in Hong Kong. Voters cast their ballots in the 7th District Council Ordinary Elections, for 88 seats in the District Council geographical constituency, and 176 seats in the District Committees constituency. These were the first elections after the relevant law was amended this past July to improve district governance. What exactly were these elections about? How were the candidates vetted?