Jainism is different mainly in the following facts:

1. It is what the Buddha described in his first sermon as 'the extreme of self torment/denial'. Henceforth it is to be rejected as not fitting for somebody seeking the end of dukkha.The main ascetic method of Jainism is extreme fasts, emaciation, going naked etc, it was declared by Buddha as conducing to more dukkha, not wise and as having no merits whatsoever.
2. Buddha was very respectful at first towards all ascetic forms as an earnest and young seeker of truth, so you may say he did practice a lot what Jains preached, before enlightenment. His own doctrine must therefore have been formulated based on the lessons he learned from this inevitable tough long journey of asceticism as a Yogi. 3)It was the Jains themselves who didn't practice as they preached, as it was later revealed, and against their own principle of 'ahimsa', they actually did involved in the hired assassination of a reknowned Buddhist Arahat, Moggallana the left hand of Buddha, whom they accused of defaming them. So I conclude that even though Buddha did teach asceticism and admitting was respectful to all forms of it, he had much to objection with the Jains, and it wont be correct to think he plagiarized them as asceticism was pretty much all the same back in those days and to combine what I said with what somebody already have stated above, there are two main objections from the Buddhist side, namely 1) their Karmic doctrine is deeply flawed ( it was a very materialistic interpretation of Kamma) and 2) their asceticism was flawed to the extreme as openly declared in the Dhammachakka Sutta by the Buddhists.

Jainism is different mainly in the following facts:

1. It is what the Buddha described in his first sermon as 'the extreme of self torment/denial'. Henceforth it is to be rejected as not fitting for somebody seeking the end of dukkha.The main ascetic method of Jainism is extreme fasts, emaciation, going naked etc, it was declared by Buddha as conducing to more dukkha, not wise and as having no merits whatsoever.
2. Buddha was very respectful at first towards all ascetic forms as an earnest and young seeker of truth, so you may say he did practice a lot what Jains preached, before enlightenment. His own doctrine must therefore have been formulated based on the lessons he learned from this inevitable tough long journey of asceticism as a Yogi. 3)It was the Jains themselves who didn't practice as they preached, as it was later revealed, and against their own principle of 'ahimsa', they actually did involved in the hired assassination of a reknowned Buddhist Arahat, Moggallana the left hand of Buddha, whom they accused of defaming them. So I conclude that even though Buddha did teach asceticism and admitting was respectful to all forms of it, he had much to objection with the Jains, and it wont be correct to think he plagiarized them as asceticism was pretty much all the same back in those days and to combine what I said with what somebody already have stated above, there are two main objections from the Buddhist side, namely 1) their Karmic doctrine is deeply flawed ( it was a very materialistic interpretation of Kamma) and 2) their asceticism was flawed to the extreme as openly declared in the Dhammachakka Sutta by the Buddhists.

Last but not the least, yes, when you come to a deeper level of understanding, the distinction between what is Buddhist and Jainist becomes meaningless or irrelevant as there may be instances in the both scriptures where they are drawing parallel references to one root, one lineage, the lineage of ancient kings and sages of India, and just because of that you should not be so biased as to say we plagiarized from them. And Buddha did admit he alone was the true Buddha of the era, and Mahavir wasn't a true Buddha, as no two lions can live inside one cage and no more than one Sun should appear at the same time, lest we all burn from the combined heat.