Intelligence is having the ability to gain and understand information, and then apply that knowledge. Emotional intelligence is having intelligence on emotions, yours and others around you. Emotional intelligence is having the ability to identify your emotional state, and use that knowledge to act in a manner with to produce the best outcome rather than lettting the emotion overwhelm you and that make you act in a non-positive way.
IQ is a measure of ones ability to understand ideas, and apply that knowledge but in a more real world, and logical sence. IQ generally has been used to measure how "smart" a person is, and usually correlates to how well someone can learn. However, EQ has become a more sought out trait from employers, because better EQ indicates a person can work better withselves and others.
EQ is important in general, because having good EQ means a person has a good grasp of their emotional being and that of those around them. This in turn, helps people to work well with others, not just in their work life, but outside it too. Ultimately, helps improve your way of living.