What is Emphasis ?
Emphasis is (noun) 1. showing the importance of something, usually in speech Don’t put too much emphasis on his age. She banged the table for emphasis as she spoke. 2. the loudness of your voice when you pronounce a word or phrase Everyone noticed the emphasis he put on the word ‘peace’. (NOTE: [all senses] The plural is emphases.)
source: Easier English, Student Dictionary Upper Intermediate Level