What or who is Buddha ?

Buddha is the Enlightened One who taught his followers, the Buddhists, to do good deeds and how to be free from misery.

What are Buddha's teachings ?

Buddha taught us to realize the 4 Noble Truths,

which are :- 

1. Misery

2. The cause of misery

3. The cessation of misery

4. The path of how to end the misery

What is the difference between Buddha and Jesus Christ or Mohamed ?

All religions teach us to be kind and have compassion. But Buddha also taught us how to break through the circle of misery which consists of being born, being old, being sick, dying, facing the ever changing nature of life and all things.

What is the core of Buddha's teachings?

1. Refrain from all kind of sins.

2. Do good deeds.

3. Purify your mind.

How can you purify the mind ? And why is the mind considered dirty ?

The mind is considered dirty or impure because human beings always react with emotions such as anger, hatred, desire, craving and aversion. These emotions only make the mind unhappy.

A purified mind looks clean and feels good.

In order to purify the mind Buddha taught us to stop reacting emotionally. It means to just acknowledge without reacting, which requires a certain knowledge. This knowledge can be reached by the Vipasana Meditation.

Why does Buddha's image always look so peaceful and harmonious ?

Because his mind is free from anger, hatred, craving and aversion. He defined such emotions as the cause of misery. And since he is free from them he has a calm heart and is compassionate, which is reflected in his image.