It means clearing or cutting of trees or forests over large area.
Forests are cut so that land can be used for different purposes like building houses,making roads etc
What are the causes of deforestation?
Trees are cut for-
Trees are cut to Provide Land for Agriculture and Cultivation
Trees are cut to Provide Land for Houses and Factories
Furniture and Paper
Trees are cut to obtain wood .Wood from trees are used to make Furniture
Wood from trees is burnt and used as fuel for cooking etc
Deforestation also happens due to natural causes like forest fires,drought etc