There are various paths of yoga which can be followed by an individual depending on temperament and objectives to be achieved. All the different paths of yoga are not mutually exclusive but are intertwined for purifying the mind and body.
The classical aim of a yogi (one who is devoted to yoga) is to achieve the union with Brahman or God. But all people practicing yoga do not want to become yogis. In modern world most of the people practice yoga for a healthy body and peace of mind. So do not worry about the types of yoga at the beginners stage. A beginner to yoga will generally start with hatha yoga that is asanas and pranayam
Bhakti yoga is the path of surrender through love and devotion. A true follower of Bhakti yoga is detached from the worldly pleasures unaffected by happiness or sorrow. He has absolute faith in the Supreme creator and sees him in every animate, inanimate object. He chant the Gods name and is free from hatred, greed, jealousy, egoism and lust.
Jnana yoga is the path of knowledge. It is the process of elevation to spiritual consciousness through the cultivation of philosophical knowledge. Jnana yoga inquires into the nature of everything including himself through discrimination and determination. Self realisation through the practice of Jnana yoga demands persistent efforts for search of knowledge.
Karma yoga is the science of karma or selfless action. It purifies the heart by teaching you to act selflessly, without thought of gain or reward. By detaching yourself from the fruits of your actions and offering them up to God, you learn to sublimate the ego. Karma yoga is based on the concept that all individuals will have to bear the effect of all their actions, it may be immediate or it may take time.
Raja Yoga translated literally means "King of Yogas". It is path of stillness, whose goal is to quieten the mind. Mind is withdrawn from all earthy attachments through meditation to create a state of focused, unbroken concentration.
Asstanga yoga is often known as the eight fold path of yoga as told by sage Patanjali. The sage Patanjali (200 BC) taught a comprehensive yoga system that became a spiritual school unto itself. According to Patanjali, in order to experience true reality one must transcend the body and mind. In his Yoga Sutras he outlined the following special stages:
Hatha yoga is known as the path of inner power. It is the science of physical exercises most familiar to beginners to yoga. In hatha yoga the mind, body and spirit are linked. The physical and spiritual purification is achieved by asanas, pranayama and kriyas to enhance mental and spiritual development. Hatha yoga consists of a number of asanas and breathing exercises. Practice of asanas regularly produces remarkable effects on mind and body. Various cleansing techniques, called kriyas, of the nasal passages, throat, eyes, stomach and bowels can be practiced in conjunction with asanas.
There are many other types of yoga or various schools of yoga like Bikram yoga, Iyengar yoga but they are all derivatives of basic paths of yoga as discussed above.