dd without any options

What does dd command do when ran without any options ?

[hannah@lenovo ~]$ dd

^C0+0 records in
0+0 records out
0 bytes copied, 7.71982 s, 0.0 kB/s

Does it delete any files or it's nothing to worry about ? Googling didn't help

Thanks in advance

What does dd command do when ran without any options?

The dd utility shall copy the specified input file to the specified output file with possible conversions using specific input and output block sizes. […]

if=file
Specify the input pathname; the default is standard input.
of=file
Specify the output pathname; the default is standard output.

^{(source; emphasis mine)}

Bare dd is like bare cat. The difference is in buffering: with dd you won't see lines printed right away. Still if you type something and hit Ctrl+d (twice if needed) then dd will print it.

Does it delete any files or it's nothing to worry about?

It doesn't. Nothing to worry about.