What is a difference between an MSc(Eng) and an MEng?

I study civil engineering, and I am going into my 3rd year on the BEng course, however if I change programme now, I can get on the MEng course, but if I finish my BEng in one year's time and then decide I want to do a Master's degree, I will be given a MSc(Eng) It makes no sense really as I will be doing the same work. I want to know what would be the best move really.