The CSS transition property is a shorthand property for transition-property, transition-duration, transition-timing-function, and transition-delay. It allows to define the transition between two states of an element. Different states may be defined using pseudo-classes like :hover or :active or dynamically set using JavaScript.

[Webplatform](http://docs.webplatform.org/wiki/css/properties/transition "Webplatform")
[Mozilla docs](https://developer.mozilla.org/en-US/docs/Web/CSS/transition "Mozilla")
[Caniuse](http://caniuse.com/#feat=css-transition "Caniuse")