Lead segmentation is a technical term for dividing your target market (Leads) into smaller groups which have common traits or interests which call for different targeting strategies.
In order to segment your leads successfully, you should have a strong understanding of who your target audiences are and what they respond well to. Segmented contact lists are only useful if you know how to follow up with each group and each group responds to the segment they have been placed in. This means not just having groups that make sense for your targeting but also having questions that group leads correctly.