Territory Management is a system by which customer accounts are grouped based on a defined set of criteria. This makes for easy sharing of customer accounts among different sales teams in your company. It ensures proper and effective usage of the sales force to maximize sales opportunities, provide excellent customer service and expand the existing customer relationships.

Here's a link to an Overview Article on :

https://help.zoho.com/portal/en/kb/crm/users-and-control/territory-management/articles/territory-management

 For assistance in determining if you need Territory Management in Zoho CRM...  Also See: Decision Guide for Territory Management