1Vendor CSS usually refers to code that is browser specific. Typically
2prefixes:
3
4-webkit- (Chrome, Safari, newer versions of Opera, almost all iOS browsers including Firefox for iOS; basically, any WebKit based browser)
5-moz- (Firefox)
6-o- (old pre-WebKit versions of Opera)
7-ms- (Internet Explorer and Microsoft Edge)
8
9They exist to allow browsers have users use new features in testing.