What's the difference between the Buddhist Sutra of Prajna Paramita and Prajna Paramita?

There is no difference. There is a slight difference in the use of words and expressions, but the main body of the scripture is the same. At present, there are seven Chinese versions of the Heart Sutra handed down from generation to generation:

Maha Prajnaparamita Prajnaparamita Prajnaparamita Mantra Sutra translated by Yao Qin and Sanzang Kumarajiva

Prajnaparamita Prajnaparamita Sutra translated by Master Xuanzang of Tang Sanzang

Prajnaparamita Prajnaparamita Prajnaparamita Sutra of Universal Wisdom

retranslated by Tang Mojie and Sanzang of China. Li Yan et al. translated

Prajna Paramita Heart Sutra

Prajna Paramita Heart Sutra-Dunhuang Stone Room Book translated by Saman Facheng, a Tang Sanzang mage

Buddha said the Prajna Paramita Heart Sutra, translated by Sanzang Shihu.