one just like abbreviation , it's only a sign , maybe it's easy to write and look elegant .

& is called an ampersand. It is a logogram which represents "and." It is typically reserved for titles or names, such as, Tiffany & Co. I would not use it when writing. The following would be incorrect: He went to the store & bought some apples.

Yes, they have exactly the same meaning. But be careful, it may be considerate as impolite to use &.