If you want to use it as a wallet, you can still run it pruned and discard the unnecessary files
So I can run a single node on a low spaced hard-disk? Should this be when installing the bitcoin core interface? Thanks
Keep in mind that full nodes have high bandwidth requirements. About 30GB of blocks needs to be downloaded monthly, and the entire blockchain which is about 300GB needs to be downloaded at first run. To save disk space you can enable pruning in bitcoin core, this throws away the blocks after it validates them causing the disk usage to be only around 2GB as ranochigo said (will be larger depending on how many blocks you retain, see below)
A normal full node also has to upload several hundred gigabytes of block data to other peers (my node with about 80 peers has uploaded 1.8TB in the past month). Because pruned nodes don't retain the blocks, they skip uploading them to peers, saving you all that upload bandwidth, but you still must sustain the download requirements.
To turn on pruning you need to type
prune=N in your bitcoin.conf file, where N is at least 550 (keep the last 550 blocks on disk), 0 turns off pruning. It cannot be changed at runtime.