Baby yarn question

[pbs]

What does "DK" mean when it says something like "Comfort DK"? Also what is "fingering weight"? I'm doing a small blankie and I started it with Comfort yarn, but it seems too "blobby" and "big" for a baby--I like neat stitches, all perfectly lined up and the Comfort isn't getting it. My LYS told me it would take me forever to make one using smaller tighter yarn, but I'm not having fun with this big unravely stuff. Any suggestions for Miss Neatnick here? BTW, I'm a beginner, so it's only garter stitch.