Clouds form when air cools to its dew point and the water vapour in the air condenses into water droplets and/ or ice crystals. There are many different types of cloud, but it is often difficult to distinguish between the clouds as they are constantly changing.
The current convention is to describe clouds using a classification proposed by Luke Howard in 1803. This is a descriptive method of classification, using some of the following latin words...

• Cirrus: a lock of curly hair.
• Cumulus: a heap or pile.
• Stratus: a layer.
• Nimbus: rain-bearing.

By using combination of these, and using the prefix -alto for middl level clouds, he described the majority of clouds that we see.

Here are some of the different types of clouds:

• Low level clouds
  • Nimbostratus
• Mid level clouds
  • Altocumulus
  • Stratocumulus
• High Level clouds
  • CirroStratus
  • Cirrus
• Vertically developed clouds
  • Fair weather cumulus
  • Cumulonimbus
• Other cloud types
  • Vapour trails
  • Billow clouds
  • Mammatus
  • Orographic
  • Pileus

The latin names do not classify enough variety of different types of cloud for research purposes and so there is a further, more detailed cloud classifications, see cloud type codes.