Data reader
 1. It is a read only and forward only data.
2. U can access one table at time.
3. It can't persist the data.
4. It is comes under connected architecture.
5. One of the most advantage is it is much faster than dataadapter

Data set
1. It is defined with multiple tables.
2. It can persist the data.
3. It is a relational data cache hosted in applicationdomain during execution.
4. It is a disconnected architecture.
5. It can't defined without data adapter.