Breakdown of Le train est plus rapide que le bus.
Questions & Answers about Le train est plus rapide que le bus.
French usually needs an article before nouns much more often than English does.
So:
- le train = the train
- le bus = the bus
Even when English might say something more generally, French often still keeps the article. So this sentence is perfectly normal with le before both nouns.
Also, both train and bus are masculine nouns, so they take le in the singular.