What is the difference between these jobs in cron?

Question

Task Schedulers

Hello, please decipher, I am adding tasks to cron via ISP.
What is the difference between these records?
I need them to just execute, no output needed.

wget -O /dev/null -q 'http://site.ru/make'
wget -O -q 'http://site.ru/make'
wget 'http://site.ru/make'

In ISP, the first task ends up looking like this:

wget -O /dev/null -q 'http://site.ru/make' >/dev/null 2>&1

Is /dev/null needed after -O then?
Thank you.