Muslim scientists contributed to many fields, including philosophy[1], astronomy[2], medicine[3], mathematics[4], and chemistry[5]. It was very common for scholars to make contributions in multiple fields, so you'll see a lot of repetition.

One of the key contributions that in my opinion influenced the Renaissance greatly was the work by numerous Muslim translators on the translation of Greek works to Arabic. In the process, many of the works of the great Greek thinkers and philosophers were preserved for future scholars. Also, Muslim scholars were responsible for bringing works from the East (China, India, etc.) back to Baghdad, making them more accessible to the West.

Arabic was so widely used that it was the lingua franca for most of science for a period of time (~12th century). European scholars who wanted to learn more about the latest discoveries and inventions had to learn Arabic at one of the large learning centers (Baghdad, Damascus, Granada, among others). Sicily[6] was another place where East and West combined for the sake of learning.

[1]: https://en.wikipedia.org/wiki/List_of_Muslim_philosophers

[2]: https://en.wikipedia.org/wiki/List_of_Muslim_astronomers

[3]: https://en.wikipedia.org/wiki/List_of_Muslim_doctors?wprov=s...

[4]: https://en.wikipedia.org/wiki/Mathematics_in_medieval_Islam?...

[5]: https://en.wikipedia.org/wiki/Alchemy_and_chemistry_in_medie...

[6]: http://archive.aramcoworld.com/issue/197806/muslim.sicily.ht...