Cirrus: high ice crystals, thin & wispy
Cirrostratus: hazy, often with a halo
Cirrocumulus: high & thin, but lumpy
Altostratus: mid level uniform grey sheets
Altocumulus: mid level bunches
Stratus: low uniform grey layers
Stratocumulus: clumped together in layers
Nimbostratus: "Rain Layers", typical grey rainy day
Cumulus: what most people call a cloud.
Cumulonimbus: dramatic rising cloud often announcing storms