سلام خانم -며 means "and at the same time" and have two main usages. 1. used as meaning of "and, or" 이것은 책상이며 저것은 의자이다. This is a table and that is a chair 그녀는 노래며 연주며 모두 잘하는 음악가이다. She is a musician who are good at singing and playing. 2. used as meaning of "while, as, over, during, with" same to "-면서" 면서 is more commonly used as spoken language than 며. 나는 신문을 보며(면서) 밥을 먹었다. I read newspaper and ate food at the same time. While reading newspaper, I ate food. 그것은 행복이며 기쁨이다. It is happiness and also pleasure.

-(으)며 is one of the verb and adjective connective endings similar in function to the English "and". It has two major senses: 1) "and" as an enumerator. "이것은 책상이며 저것은 의자이다" (This is a desk, and that is a chair). In this usage, it is equivalent to -고. "이것은 책상이고 저것은 의자이다". 2) "doing/being something at the same time". "학교에 간다고 하며 나갔다" (He went out saying he's off to school). This sense is equivalent to -면서. "학교에 간다고 하면서 나갔다". Examples: - 남편은 친절하며 부인은 인정이 많다 (The husband is nice and the wife very kind). - 서울은 한국의 수도이며 제일 큰 도시이다 (Seoul is the capital as well as the largest city of Korea). - 아이는 소리를 지르며 뛰어다녔다 (The child jumped around screaming). - 어머니는 동생 머리를 쓰다듬으며 말씀하셨다 (Mother said while caressing my little brother's head).

Hi ! :D nice to meet you :D