The CBD Isolate is a crystalline solid or powder that contains pure CBD.
During the production process of CBD Isolate all the other cannabinoids and plant impurities are removed.
The CBD powder or CBD Isolate can provide more benefits than the CBD Oil.
I've never personally used any CBD Isolate or CBD oil or any other CBD products but many people have and they say that the CBD Isolate is usually better than the CBD oil for most people.
But of course it depends on your preferences and you might like one over the other.