The marinara sauce and pizza sauce is similar and are made using the same ingredients.
However marinara sauce uses cooked tomatoes that are cooked ahead of time and pizza sauce uses raw tomatoes.
You can use marinara sauce on pizza if you want too and I have done it myself when I ran out of pizza sauce but wanted to make homemade pizza.
I used the marinara sauce instead of pizza sauce and the pizza with the marinara sauce turned out just fine.
I actually liked the pizza better using the marinara sauce instead of the pizza sauce.
So yes in some ways the marinara sauce is similar and somewhat the same as pizza sauce but the pizza sauce uses raw tomatoes while marinara sauce uses cooked tomatoes.