WHAT IS NO NC CONTACTS AND WHY NC NO CONTACTS CALLED AS AUXILIARY CONTACTS

WHAT IS NO NC CONTACTS AND WHY NC NO CONTACTS CALLED AS AUXILIARY CONTACTS. Hello Friends welcome to Our You Tube channel ‘S S KUMAR TELUGU E TECH' so That you can learn what is Electric Current, how to use Electric Current in Our house, how many types we can use electric Current ? what precautions we have to use in Electric Current, about Diesel Generators, Motors, Motors control wiring, Magnetic Contactors, Batching Plants, Hoists, Tower cranes Distribution Transformer, Air Conditioners, UPS ,Air Circuit Breaker, V.C.B, and how to do it's Maintenance, I Will try to explained in TELUGU with safety.