Energy efficiency classes are graded on a scale from A+++ to G - A+++ being more energy efficient. The energy label is applicable to most white goods, cars, light bulbs etc. According to EU directives (92/75/CEE, 94/2/CE, 95/12/CE, 96/89/CE, 2003/66/CE), the label must be displayed.
A+, A++ and A+++ are most energy effective. Those grades was introduced at a later stage.