Beauty

Genuine question; I'm new to makeup, please be gentle :)

I'm very new to skincare and i don't know a lot but i had a question and i think this is the right place for it. There's a serum and a toner from the same brand both of which have the same ingredients (as far as i could tell), the difference is that one is a serum while the other is a toner. What differences are there? Should i get another toner and get the serum? Or get them both?