Single Day
In short
A single day race is a professional road cycling event that is completed within one day rather than over several stages.
In plain words
Most big cycling tours last for many days, but these races are finished in one go. They are often very long and difficult. The most famous ones are called the monuments.
A simple example
A rider starts at a village in the morning and must reach the finish line before the day ends. They do not sleep in a team hotel overnight to start a new stage.
Why it matters
These races are highly prestigious and test a rider's endurance and tactical skill in a single burst. They are central to the professional cycling calendar.
Easy to mix up
Do not confuse them with stage races, like the Tour de France, which take place over many days.