Why people use prefix css

Question

-webkit-box-sizing:border-box
Box-sizing: border-box;

Why people use these two? Both are same right? And why did they left space for "box-sizing" Of 2nd line

Answer 1

Both are the same. CSS vendor prefixes are a way to add support for new CSS features before those features are fully supported in all browsers.

If you don't know, What CSS to prefix?
check this http://shouldiprefix.com/

Answer 2

Sainath Dora
Vendor prefix are used to support different properties on different browsers.
Like -webkit- is for chrome or safari etc, -moz- is for Mozilla.

Answer to "why they leave space":
Just so code looks neat and readable, if you don't want to leave space, it's okay.

Answer 3

Yeah but why do they leave space if see second line of code they left tab space why?