Ghazals are poems that are generally sung. Their structure includes multiple couplets put together which are called sher. Each couplet may or may not be on the same topic, and are independent of each other. They have a rhyming scheme of AA BA CA DA EA and so on. The poet may choose to include his pen name in the final couplet. They follow the rules of kafiya and radif.  Nazms, on the other hand, are generally read or recited. They may have either short or long verses. They are interrelated to one another meaning that they are all written on the same topic. The rhyming scheme is that of the poet’s preference. The poet does not include their pen name in a Nazm and it is not necessary to follow the rules of kafiya or radif.