Gelato originated in Italy whereas ice cream finds its roots in ancient China.
Ice cream typically contains 10% to 18% cream whereas gelato contains 3% to 8% cream with more milk.
With more cream, ice cream tends to have a higher fat content than gelato.
Ice cream is churned at a high speed to introduce more air whereas gelato is churned slowly just to make the texture smooth but not include air.
Churning at high speed makes ice cream fluffy, airy and increases its volume; on the other hand gelato is much denser and smoother with its low speed churning.
Ice creams are served cold to hold the shape, while gelato is firmer so it's served at room temperature to make it pliable.