The seven primary mudra (hand gestures)
seen on Buddha images.

Everyone uses their hands to communicate, to ‘speak' to other people. This is another form of symbols in action. In the sign language of Buddha statues there are seven common hand gestures called 'mudra'. Some of these have a specific story from the Buddha's life to explain their origin and it seems better to relate these here rather than in the 'Life Story' section.
The images (except anjali) link to a page of pictures examplifying the mudras on various statues.

fearlessness &
The right hand is raised level with the shoulder, palm facing outwards.
The Buddha had a younger cousin, Devadatta, with who there had been regular problems through his life. Devadatta did eventually ordain as a monk but gradually became jealous of his cousin and wished to take control of the Sangha. The Buddha of course refused his requests so Devadatta tried to kill him - on three occassions. For the last attempt he made one of the royal elephants, Nalagiri, very drunk and beat it with sticks then sent it charging down the street where the Buddha was walking on alms round with Ananda, his attendant. Ananda freaked out and called to the Buddha to run away. The Buddha calmly stood still and his heart was filled with compassion as he saw the pain the elephant was in. He fearlessly raised his right hand and radiated love and kindness toward the elephant who gradually slowed, eventually kneeling at the Buddha's feet.

At the time of the Buddha's enlightenment he was sitting serenely under the Bodhi tree. Mara, the personification of temptation, saw this and was greatly troubled. Mara's business is to fuel people's greed and anger, making them mentally confused, so anyone who was going to get enlightened was a threat to Mara's business - can't have people going around teaching folk to be generous, compassionate and clear minded! Can we?
So Mara came before the Buddha with a great army [these are our mind states] of both the monstrously ugly and fearsome and the wonderfully beautiful (usually depicted as Mara's three daughters) and he laid a challenge before the Buddha:
'What right do you have to sit on the throne of enlightenment? and the Buddha gently reached down and touched the earth saying: 'I call the earth as my witness to this right.' Then Mother Earth rose from the ground and said to the Buddha: 'For every good dead that you have done I will wring one drop of water from my hair.' and such was the great flood of water that followed that the armies of Mara were swept away. [a bit like the Noah's ark story? - purification.]

calling the earth
to witness

The right hand is extended down - palm inward - with the finger tips reaching just below the knee.

The hand is extended downwards, palm open and facing out.
Sunita was a scavenger born into the so called outcast community. The Buddha was on his morning alms-round one day and happened to pass Sunita. Such was the Buddha's radiance that the humble youth prostrated himself before the Master in adoration. As the Buddha talked to him he raised one hand in the gesture of loving-kindness and the other in that of giving.
The greatest gift anyone can recieve is freedom - true freedom comes with the gift of knowledge - teachings.
This gesture is one of generally teaching. It can be seen as half of a dhammacakka mudra [c.f.]. There are many stories of the Buddha giving teachings and no particular one is fixed in relation to this mudra.
The core of the Buddha's teaching is the Four Noble Truths and one could easily imagine this list being taught - one by one. The hand is raised and the thumb touched the forefinger: 'The first Noble Truth is ....'
Some images can be seen with the thumb touching the other fingers: 'The second .... the third ... '

The hand is raised with the thumb (usually) touching the forefinger.
The first sermon
The hands are raised before the heart; thumb and forefinger of each hand touching.
This mudra refers directly to the Buddha's first discourse in the deer park at Sarnath.
Dhamma = the teachings, nature, the law, the way
Cakka = wheel, blessing, weapon. [see: SYMBOLS]
The meeting of the thumb and forefinger form a circle - a wheel. The four fingers of one hand represent the Four Noble Truths and all eight fingers the Eightfold Path. The contact of various other fingers between hands is sometimes given meaning.

A common gesture of greeting, respect and reverence - usually offered between equals, or from junior to senior. As the Buddha is the most senior of all, it is rarely found on a Buddha statue.
The symbology is manifold.
It is a symbol of unity where the two opposites: the left and the right, the black and white, yin and yang, male and female, etc - i.e. the whole dichotomous universe - comes together as one. This is the idea behind this web site: the Buddha Mind.
This union takes occurs over the heart centre - the place of emotion, of love, etc. There is much written in yogic texts about this cakra.
The hands form the shape of a lotus bud - a potent image in itself, rich with symbolism.
The hands can also be seen as forming a diamond (shape). With the two 'worlds' joined the resulting union is seen as symbolic of the eternal, indestructible truth that is the Dhamma.
The intelocking ten fingers represent the ten paramittas - the virtues [see: TEACHINGS - NUMBER GROUPS]

Resepect & Greeting
Both hands raised before the heart, palms facing.
Dhyana is a derivative of the Pali word 'jhana' = absorption, concentration and is a direct reference to meditation. The same word is found as Cha'an - a Chinese school of Buddhism which places emphasis on meditation. Zen is the Japanese form of Cha'an; and so the linguistic link reveals a lineage.
The mudra is one of meditation.
When you sit down on the floor cross legged the hands quite naturally fall into the lap, one on top of the other. There are various exotic forms of the basic mudra with a range of symbolism.