I was thinking of how to explain it but will let wikipedia say it for me,
Affiliates of SprintNextel Corp. and Sprint Rural Alliance
CDMA Affiliates: Swiftel in Brookings, South Dakota;[9] Shentel in northern Virginia, and parts of Pennsylvania, Maryland and West Virginia.
CDMA Partners (SRA Members): Alaska DigiTel in Alaska; NTelos in West Virginia, and western Virginia; NexTech Wireless in Kansas, and part of Colorado; Pioneer Cellular in Kansas and Oklahoma, in which their agreement ends on March 1, 2012.
Sprint Affiliates are those carriers who use the Sprint name to offer their services yet operate their own network and use Sprint SIDs.
Sprint Partners are those carriers who use their own equipment and also sell their own service. In addition to allowing Sprint to use their equipment, they allow Sprint to hold their licenses in that area.
Sprint Partners are known as "Sprint Rural Alliance" (SRA).