Explain the difference between CSS2 & CSS3?

CSS2 : It was released in 1998. In CSS2 designers could only use web safe fonts for being 100% sure to use fonts that would always display the same on every system. CSS2 had "simple selectors". In CSS2, the developers or designers had difficulty because the standard was not equipped with automatically breaking of the text so that it fits within a box.

CSS3 : It was released in 1999. In CSS3 designers can use special fonts like those available in Google Fonts and Typecast. CSS3 calls the components as "a sequence of simple selectors". In CSS3 has the capability to split text sections into multiple columns so that it can be read as a newspaper.