working with fonts in css

Whats the difference in using quotes and apostrophe?

@font-face {
font-family:font family; example:"font family" or 'font family'
font-style: normal;
font-weight: normal;
src: url(fonts/font family.ttc); example: "fonts/font family.ttc" or 'fonts/font family.ttc'
}

and the div?

div.your div {
font-family:font family; example:"font family" or 'font family'