Both support windows, but only Java supports other open platforms (where you can install external software, like Linux and Mac PCs, or others OSes/HW architectures).

Bedrock is only published on closed platforms (games consoles, mostly, and app stores) and windows.

Java is the only edition that supports mods.

The android version of bedrock is also unofficially playable on Linux.

You mean Bedrock supports consoles.

Java supports Mac and Linux, so it's also multiplatform. Just different platforms.