# Static segmentation

Static segmentation is the ideal solution when you want to perform a one-time operation on existing contact groups, such as merging several lists into one or subtracting one group from another. This operation results in a new, unchangeable (static) group that you can use in the future.

### **When should you use static segmentation?**

* When you need to quickly prepare a list for a one-off campaign.
* When you need to "clean" one list of contacts that are on another (e.g., from an unsubscribe list).
* When you want to find common recipients for several different groups.

### **Available segmentations**

You can perform several types of operations on your groups. After clicking **"+ Add operation"**, you will see the following options:

* **Add contacts from other groups:** This acts as a **Union**. It creates a new group containing all unique contacts from the groups you select.
  * **Example:** You combine the "Webinar A Attendees" and "Webinar B Attendees" lists to create a single, common mailing list.
* **Remove contacts from other groups:** This acts as a **Difference**. It creates a new group that contains contacts from the main group, but without those that are also in the second, specified group.
  * **Example:** From the "All Customers" group, you remove contacts from the "Made a Purchase in June" group to send an offer only to those who haven't bought anything yet.
* **Add contacts based on filters:** Allows you to add contacts to a new group that meet specific conditions (e.g., have the SMS channel blocked).
* **Remove contacts based on filters:** Allows you to remove contacts from a new group that meet specific conditions.
* **Split group by percentage:** Allows you to randomly divide one group into several smaller, percentage-defined parts (e.g., for A/B testing).