why we use vendor prefix

Answer 1

If you don't use vendor prefixs, some css rules may be not supported according to versions of browsers used to visit your page, as prefixed properties are often not yet implemented under standardized names, but will in most recent or future versions...

Answer 2

if we not use it so..

Answer 3

Browsers might implement a particular feature, but not with the standard syntax. So, for compatibility purposes, it is expected of a designer/programmer to use the syntax specific to the browser the user is using. CSS3 features like transforms are implemented under various names like 'moz-transform', 'webkit-transform' etc.

Answer 4

https://developer.mozilla.org/en-US/docs/Glossary/Vendor_Prefix