Which is better push rod or timing chain?

If one camshaft is used, it is referred to as a SOhc or single overhead camshaft engine. Is this true? Overhead camshaft engines typically use long roller chains for each bank and a single toothed timing belt, because pushrod engines can use gears or short chains.If a camshaft is used, it is often called a SOHC engine or a single camshaft above. While pusher engines can use short speeds or chains because the camshaft is close to the camshaft, the camshaft above the camshaft usually uses long roller chains for each bench or a single timer tooth belt.