同学你好，该知识点来自沪江网校《新概念英语2、3、4册连读【双11专享班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学好
你的理解是正确的，a party of=parties of 表示：一批....；一群...
例句：
It has emerged as a powerful means for parties of every type to conduct interactions of every type.    
互联网络已成为一种威力强大的工具。凭借它，各类人都可以进行各种交互式活动。

Many politicians travel with large parties of official or private bodyguards.
很多政客会有一大帮职员和私人保镖去旅行。

The Democrats have become a party of the centre.
民主党成了中立的党派。

He saw a party of schoolchildren getting off the bus.  他看见一群学生下汽车。

祝学习愉快！