How does the $HIV$ virus affect the body and kill the affected person?

(N/A) In $HIV$ infection:
$(i)$ The virus enters the immune system and damages its function by targeting $T-helper$ cells.
$(ii)$ The body can no longer effectively fight off the many minor infections that it encounters every day.
$(iii)$ $A$ very small cold can progress into severe $Pneumonia$,and minor gut infections can lead to major diarrhea with significant blood loss,eventually leading to the death of the patient.