What's the difference between addiction and disease?

Specifically, I'm talking about alcohol and drugs. An alcoholic is said to have a disease. People who have problems with illicit drugs like cocaine, marijuana, heroin, etc, and even legal drugs like pain killers are said to be addicts. What's the difference? Isn't alcoholism a form of chemical dependency (addiction). Why is illicit drug dependency not seen as a disease? Is the difference because alcohol is socially acceptable? I submit that an alcoholic is an addict and not necessarily diseased, though liver disease may be present or coming.
Ok! I know that with a disease you have no choice. Since to drink alcohol or not is a choice WHY IS ALCOHOLISM A DISEASE? and drug abuse is not?
I know the reasons for substance abuse, no matter the substance. But WHY IS ALCHOLISM A DISEASE? while drug addiction is not?
Ok, a disease can be treated with medications or surgery. There are medications to help stop smoking and to help stop drinking and to help stop drug abuse. But you don't answer the question WHY IS ALCOHOL ABUSE A DISEASE WHILE DRUG ABUSE IS NOT? or WHY IS DRUB ABUSE AN ADDICTION AND ALCOHOL ABUSE IS A DISEASE?

: http://alcoholdrugstreatment.info/whats-the-difference-between-addiction-and-disease