# Segment definitions

Most segment selections that you create will be a **Regular segment** type of query. See [Fixed time points](<https://help.apteco.com/en/faststats/analysis/segmentation/change-over-time/fixed-time-points/index.md>) for more information on creating these. However, when you are creating a segmentation, there are other query types that you may wish or need to use.

## Segment equal to previous

Segments can be marked as being equal to the previous segment for the purposes of migration; movements between those segments are then identified as "Stay same". For example, even though you may hierarchically prioritise your segment selections, you may consider it unimportant that a person has moved from segment 2 to 3, or vice versa. In such cases, the use of this option for the purposes of migration places those people into the "Stay same" group.

## Not a customer or never a customer

The option to define a segment as 'Never a customer' - often defined as people who have had no transactions before today - allows you to differentiate between acquisitions (completely new customers) and reacquisitions (previous customers, now returning).

## Rules governing the validity of segment definitions

- You can only define one 'Not a Customer' and one 'Never a Customer' segment within a segmentation.
- You can create a segmentation without using a 'Not a Customer' or 'Never a Customer' segments but you cannot then identify acquired or lapsed customers.
- You can only create general and specific migration reports with Fixed Time Points (Reporting Points) and not Elapsed Time Points.
- You can only use the general and specific migration reports when the default setting to allow people to only be in one segment is in place.

  > **Note**
  >
  > The option to override this default sits in the Segment Settings dialog:
- You can edit the default labels used to describe the migrations so that they best suit your business terminology. Select **Edit Migration Labels** in the Segment Settings dialog: