Canon Lenses - USM vs DC

[Podie]

I'm looking at Canon EF 75-300 mm f4/5.6 Mk3 lenses… and there are two versions available… one with a USM (ultra sonic motor?) and one with a DC motor. What's the difference between the two (cost aside) and which am I best purchasing if most of my photos will be of scenery or moving objects..? (eg cars and animals)

TIA.

[Podie]

Thanks... seems odd that the USM lens is circa £20 cheaper then...!!