what is methylene chloride / dichloromethane used for?

It's widely used as pharmaceutical intermediates, 

polyurethane foaming agent / blowing agent to produce flexible PU foam, 

metal degreaser, 

metal cleaning, 

oil dewaxing, 

mold discharging agent, 

decaffeination agent, 

parting agent of detergent, 

and also in adhesive, agrochemical and film industry, etc.