What is the difference between a Bodhisatta and a Bodhisattva? Lots of Buddhist words have two different spellings (kamma/karma) because one is the Pali version and the other is the Sanskrit version; but the meaning is the same. My understanding of Bodhisatta and Bodhisattva though, is that they have different meanings. Can anyone elaborate?
Bodhisatta is Pali, Bodhisattva is Sanskrit, they have the same basic meaning.

Wikipedia:


  In Buddhism, a bodhisattva (Sanskrit: बोधिसत्त्व bodhisattva; Pali:
  बोधिसत्त bodhisatta) is an enlightenment (bodhi) being (sattva).
  Traditionally, a bodhisattva is anyone who, motivated by great
  compassion, has generated bodhicitta, which is a spontaneous wish to
  attain Buddhahood for the benefit of all sentient beings. According
  to Tibetan Buddhism, a Bodhisattva is one of the four sublime states a
  human can achieve in life (the others being an Arhat, Buddha, or
  Pratyekabuddha).


In Theravāda Buddhism, the term "bodhisatta" (Pāli language) was used by the Buddha in the Pāli canon to refer to himself both in his previous lives and as a young man in his current life, prior to his enlightenment, in the period during which he was working towards his own liberation. In later Theravāda literature, the term "bodhisatta" is used fairly frequently in the sense of someone on the path to liberation.

Mahāyāna Buddhism is based principally upon the path of a bodhisattva. Mahāyāna Buddhism encourages everyone to become bodhisattvas and to take the bodhisattva vows. With these vows, one makes the promise to work for the complete enlightenment of all sentient beings.

The vows are an expression of bodhichitta, the desire to realize enlightenment for the sake of others. The exact wording of the Bodhisattva vows varies from school to school. The most basic form is:

May I attain Buddhahood for the benefit of all sentient beings.

Mahāyāna schools like Zen, Nichiren, Tendai, and others use vows translated as:


Beings are numberless, I vow to save them
Desires are inexhaustible, I vow to end them
Dharma gates are boundless, I vow to enter them
Buddha's way is unsurpassable, I vow to become it.