"圈子"可以指一个圆圈，也常常用来说一群关系很近的人，比如朋友或者同事。

"圈子" can refer to a circle, and is often used to describe a close group of people, like friends or colleagues.

我们常说"社交圈子"或者"朋友圈子"。

We often say "社交圈子" (social circle) or "朋友圈子" (circle of friends).