What is ruby? Why using this and what advantage other language compare to this??

Answer 1

Try looking at those two threads, I think they cover the topic :)
https://www.sololearn.com/discuss/535798/?ref=app
https://www.sololearn.com/discuss/225388/?ref=app

Answer 2

Ruby is an object-oriented programming language.
Just learn it on Sololearn.

Answer 3

it's good if you learning about security