Yeah, merino is a breed of sheep. It is generally a much softer wool. Malabrigo is a wonderful, kettle dyed yarn. Gorgeous colours and a dream to knit with. It's actually a good deal because you're paying $10 - $12 for 210 yards of pure heaven.
Also good to know....merino's tend not to show cables well, but Malabrigo really holds up to cable knitting. I'm using it for my Urban Aran.