Buddha reached Enlightenment while meditating under the Bodhi Tree. For this reason, most Buddha figurines show him meditating. Sometimes you'll see him with a lotus flower or a snake, but still the most common depiction shows Buddha sitting on the ground with his legs crossed and his feet on his thighs.
Four variations on this classic pose are also significant. You'll often see Buddha extend his right hand to the ground near his right knee. This is called the "earth touching pose," and it reminds us that Buddhism doesn't recognize a distinction between people and animals in the way that Western religions do. In Buddhism, the world is not here for mankind to exploit-instead we are here to cooperate with nature and to help animals on their journey just as we help other people.
Many Buddhists believe that Buddha can grant wishes. For this reason, they decorate with a Buddha figurine showing him in the "wish giving" pose. In this pose, Buddha extends his hand toward you. He turns his palm up to offer you the wish you desire.
This concept that Buddha can grant wishes is unique to Buddhist tradition. It's different from Christian practice of praying to God or Jesus, because Buddha himself is not believed to be the Creator of the earth. It's closer to the way some Christians pray to saints for assistance but still different and unique to Buddhism.
The idea of Buddha granting wishes extends to the idea of Buddha granting blessings. Buddha can grant you peace, serenity, health, love, and a general sense of well-being. In this pose, Buddha has his hand raised near his shoulder. He turns his palm toward you in a friendly gesture of openness.
Once we recognize that Buddha can deliver blessings and grant wishes, we can see how Buddha might eliminate fear. This leads to the popular pose called "dispelling fear." This pose is quite similar to the wish giving pose. Again Buddha has his hand raised and his palm toward you. But in this pose, his hand is not quite as high-closer to his chest than his shoulder.
In the "teaching pose," Buddha is communicating one of his vital lessons. Again, you'll see him with his hand raised and his palm toward you. But, in this post, he touches his thumb and forefinger together as he makes a point. Buddha worked toward Enlightenment for many years. Once he had reached that goal, he devoted his life to helping others achieve that same desired outcome.
Finally let's consider the popular pose called the "reclining Buddha." There actually are two different versions of this. You'll see Buddha lying on his side with his head propped up in his hand. This is simply Buddha resting, and taking a break from his teaching.
The other version of the reclining Buddha shows Buddha with his lower arm on the ground. In this pose, Buddha has died and reached Nirvana. Nirvana is one of the primary goals of Buddhism, and it is a core element of the path to Enlightenment.