[Users] Increase core or socker for vCPU

Hi, I have a basic doubt, while increasing vCPU for a VM in RHEV-M, do we need to increase core or sockets? For instance, if someone asks for 2vCPU then should i make it 2 socket x 1 core or 1 socket x 2 core.. I do understand that it depends on application too to choose. but i'm asking in general. Sorry, if its not relevant to this forum. Thanks