Categorize the given task into one of the three given classes: Classification, Regression, or Clustering
Finding similarities between customers based on past purchase data.
This task falls under the category of Clustering.
Complete the following task based on the instruction and optional input provided.### Instruction:
Categorize the given task into one of the three given classes: Classification, Regression, or Clustering

### Input:
Finding similarities between customers based on past purchase data.

### Output:
This task falls under the category of Clustering.