What is UCCI UNLOCK for in my Samsung Galaxy Prevail

[AC Question]

Under System Updates on my Galaxy Prevail there is UCCI Unlock. I rap on it and only had a message that can not update. I don't know what its for. Can someone tell me more? My service is with Boost Mobile which isn't that great just so you know. Thanks.

 

[anon(632115)]

It unlocks your phone so you can use sims from other carriers