jar files

Does anyone know what jar files are and where they come from?
I am a new limewire user and have only downloaded audio files. However in the documents folder in LW I have many files that are jar files and I don't know where they came from. Can I delete them are are they essential files for LW??

I appreciate any and everyone's input.

Thanks

Hello and welcome, these jar files are part of LW, I came accross them when I was unistalling an old version of lw, you cant delete them as you will get the message their being used by another program, so their nothing to worry about....