What software should I use to create a 2D animation video like a pro?


Hello everyone!

My name is guy, I am a beginner in animation studies and I want to specialize in this field.
I’ve read a little bit about 2d animated videos & flash animation, But I didn’t really understand what software is the most recommended to start with.

I saw some cool animation videos at pilanimation company’s website
And i want to be able to do the same in the future.

Which software do you guys recommend?