Hello, DingTalk groups are divided into Secured Enterprise Group, All-hands Group, Department Group and General Group;
[Secured Enterprise Group]: only the person in the enterprise contacts can enter the group, if the employees exit from the enterprise contacts, they will automatically exit from the Enterprise Group;
[All-hands Group & Department Group]：
a. The department group is associated with the staff structure of the department. The employees joining the department will automatically join the group, and will automatically withdraw from the group when leaving the department;
b. The Enterprise Group is related to the employee structure of the company. The employees who join the company will automatically join the entire staff group, and will automatically withdraw from the entire staff after leaving the company;
[General Group]：No department or company restrictions, as long as the person is the DingTalk users can join.

[Tips]
1. Secured Enterprise Group, Department Group, and All-hands Group cannot be transformed into each other;
2. Secured Enterprise Group cannot be changed to General Group;
3. If a general group has members all from same team/enterprise, you can upgrade the group to Secured Enterprise Group: group admin can go to "DingTalk Mobile APP" - "group chat" - upper right side "Group Setting (Portrait Icons)" - "Group Type" - "Secured Enterprise Group"