When Buddhism spread to China, the long Indian place names of the Buddha's homeland and personal names of his associates had to be represented by Chinese Characters. The characters were usually selected for their sound and deliberately divorced from their normal meanings. Sometimes characters were intended to be pronounced in "secondary" readings, i.e., differently from in ordinary prose, a phenomenon that has become worse as the centuries have passed and the phonology of spoken Chinese has evolved.
Sometimes new characters were invented, often by putting a little square "mouth" before a standard character. Some characters have no colloquial use except in Buddhist contexts.
Different translators made different decisions. For example, Lady Yaśodharā, (also spelled Yasodharā and Yashodhara), the buddha's wife, has been transliterated into Chinese as Yéshūtuóluó 耶输陀罗, Yéshūtuó 耶输陀, Yéshūduōluó 耶输多罗, and Yéshùdáluó 耶戍达罗. The kingdom of Magadha has been rendered as Mójiētuó 摩揭陀, Mójiétí 摩竭提, Móqiétuó 摩伽陀, and Móhētuó 摩诃陀.
Over time, some expressions were shortened, and others became customary, but very few have ever been thought beautiful.
With philosophical vocabulary the problem is worse. Some translators preferred polysyllabic transliteration, which produced long series of characters with no obvious surface meaning, requiring that a reader have expert instruction to make sense of a text.
Others preferred translation into words already used in very un-Buddhist ways, which risked distorting the ideas being translated.
For example, paribbājaka refers to religious mendicancy in Pali. But it was rendered into Chinese as chūjiā xiūdào 出家修道, literally "leave the family and practice the Way." To abandon a family would always have been a terrible fate (or a terrible dereliction of duty) in China, which had no tradition of religious mendicancy comparable to that of India. And the "way" (dào 道), of course, was already a loaded term in Chinese, so using it to render an Indian idea was almost begging for misinterpretation.
It is safe to say that most Chinese through most of history have found Buddhist vocabulary generally puzzling, and have regarded the transliterated technical terms and proper names associated with Buddhism to be among the most cumbersome linguistic entities in their language.
For western students of Chinese Buddhism, the use in English of the original Sanskrit and Pali names (unknown to Chinese Buddhists) rather than or along side of the Chinese ones is an additional barrier. For example, rendering the same person's name as Guānyīn in one place and as Avalokitesvara (or even "Lord Who Looks Down") in another place does not make the study of Chinese Buddhism any easier.
Further, the badness of fit between the sounds of Indian languages and those of English is almost as great as with Chinese, and the various diacritics that specialists place over and under Romanized Sanskrit and Pali are mere clutter to the English reader, who cannot pronounce the difference they are intended to indicate. In addition, they are unavailable or hard to access in most type fonts, including computer type fonts. (Unlike Chinese, where very short words borrowed into English may vary only in tone and become inaccurate when the diacritic is removed — such as the difference between the Jīn 金 dynasty and the Jìn 晋 dynasty — imported Indian words are usually polysyllabic and hence have considerable redundancy.)
The conventions followed in the present retelling of the life of the Buddha are laid out in the introduction. The listing at the right of the screen may also be helpful in some cases.
An excellent on-line source on the Indian words underlying the Chinese transcriptions is the full text of the famous Dictionary of Chinese Buddhist Terms by William Soothill and Lewis Hodous. (Caution: The dictionary is presented as a single web-page nearly 4 megabytes in length, so it takes a while for a browser to manipulate it.)
Somewhat more accessible, if less learnèd, online glossaries are available, but most URLs for them seem to be discouragingly short-lived.
For serious anglophone students of Buddhism, the best resource is The Princeton Dictionary of Buddhism by Robert E. Buswell, Jr. and Donald S. Lopez, Jr. (Princeton, NJ: Princeton U. Press, 2014. 1265 pp. ISBN: 978-0-691-15786-3. LC: BQ130.P75 2013. Published at $65.) It provides excellent explanations of philosophical terms and written works, as well as fulsome identifications of many places and people, all with ample linguistic detail for the many languages associated with Buddhism (Pali, Sanskrit, Tibetan, Chinese, Korean, Japanese, Vietnamese, and sometimes others).