Buddhist Key Terms

Buddha:
The awakened one/enlightened one. The goal of Buddhist religious practice, and an epithet for Prince Siddhartha Gotama.

Dharma:
The doctrine. The teachings of the Buddha.

Sangha:
The assembly. Sometimes refers to the assembly of all followers of the Buddha or only the noble or awakened Sangha.

The Three Jewels:
This refers to Buddha, Dharma and Sangha (see above). 

Arhat:
Foe-destroyer. Name for a practitioner who has obtained liberation from Samsara. Different meanings: (1) An epithet for the Buddha (2) According to the Mahayana: name for the highest level of realization possible for a practitioner of the Shravakayana.   

Bodhisattva
One who strives for awakening. (1) acc. to the Theravada this refers to the Buddha before attaining awakening. (2) acc. to the Mahayana it refers to a practitioner who has developed the mind of awakening (bodhicitta), and consequently strives to achieve awakening in order to liberate all sentient beings.