Why Are Drugs and Alcohol so Seperated?

When people talk about "harmful" substances they always say "Drugs and Alcohol." Why is it that they are separated in common speech? People are saying it like they are two completely different things but what truly is the difference? "A drug is any chemical or biological substance, synthetic or non-synthetic, that when taken into the organism's body, will in some way alter the functions of that organism." So wouldn't everyone agree that alcohol does just that, alters the organisms functions? Marijuana does the same thing, alters the organisms functions. Most people would say that alcohol isn't a drug because it has less negative effects than "drugs" such as Marijuana.

So many people die so often from the effects of alcohol even if they have never touched it. Drunk driving is the number one automobile related death in the world not just for the person under the influence of alcohol but what about the people they often hit?

If not automobile related alcohol has many negative effects including "...can cause acute respiratory failure or death" plus many other negative health problems such as "permanent damage to vital organs such as the brain and liver. In addition, mothers who drink alcohol during pregnancy may give birth to infants with fetal alcohol syndrome. These infants may suffer from mental retardation and other irreversible physical abnormalities. In addition, research indicates that children of alcoholic parents are at greater risk than other children of becoming alcoholics."