Scratch space is a disk server that you can use to store whatever file you want.
On scratch space, you can store any number of files of any dimension (compatibly with the overall disk space at disposition). No checks will be performed to the files contained in this server, and no backup of these files will be performed either.
To access the scratch files all you have to do is connecting to the directory scratch /scratch/<username> by using Linux and you can use the disk space for your needs. Recall that even others users needs to use the scratch space, so be gentle when you store your files.
Currently the scratch space has around 4 TByte for storage. It's a large amount of space just for files that one want to access but that aren't vital.