Question

what is hello why we use this word

Answer 1

The dictionary says it was Thomas Edison who put hello into common usage. He urged the people who used his phone to say "hello" when answering. His rival, Alexander Graham Bell, thought the better word was "ahoy."

Answer 2

Hello is word for greeting..people who didn't say hello where considered as rude..As for example.. Usually people attends a call with a hello..if they doesn't say usually we peoples gets angry..So it can be also called as some respective sense of word
Hope it helps u