Yoga is a 'living tradition', a physical and mental system for growth and self-development. It is as relevant and effective today as it has been for centuries.
The word Yoga means 'union' or to 'join together' and by practicing yoga your aim is to feel balanced by connecting with mind, body and spirit.
One of the reasons yoga has become so popular recently is because yoga can give you real tools to deal with life's frenetic pace. As you deal with life's stresses/strains yoga reminds you to stay calm, balanced and centred, just as you practice feeling balanced in a physical pose, so you begin to integrate this aspect into all areas of your life.