In simple terms deportation and exclusion have the same consequences. However deportation is a process of removing the person who is already living in the United States. Exclusion is a process where a person arriving in United States is not allowed to enter.
The legal proceedings for both the cases differ in some ways. The reasons why a person may be excluded from entering the country can be health reasons, possession of illegal drugs like marijuana or cocaine or violation of any of the airport laws. The reasons for deportation may be breaking the law, overstaying the visa permit, or involved in criminal activity, working illegally, and going against the rules set by the immigration and naturalization services.
Exclusion that has been caused by illnesses and health grounds may be temporary. If you have been affected by some kind of virus you can be cordoned in the airport premises until you have been treated. However exclusion on the basis of criminal grounds can be permanent and you may never be allowed to enter the country again. Deportation also similarly can take place for a brief period of time and at a later point you may be allowed into the country depending on the act.
However if it is anything to do with breaking the laws or engaged in criminal activities in that case deportation is a permanent remedy. That is why it very important to watch your luggage and not leave it unguarded in airports. Also drugs and marijuana are taken very seriously by the officials at the airport.