Breakers
There are certain letters in the Urdu alphabet that cannot be connected on the left (to the next letter). These letters break the flow of a pen within a word. These letters are called “Breakers”.
The Breakers are shown here.
Since they cannot be left-connected, Breakers only have two possible forms: Detached (non-connected) and Final (right-connected).
Think about how the occurrence of a Breaker affects the writing of a word.
When every letter in a word (or every letter but the last) is a Breaker, then each letter appears in its Detached form.
For example:
د ر و ا ز ہ