The phrase "can't hold a candle to" means that someone or something is not nearly as good as someone or something else. 

The origin of this phrase dates back to a time when candles were a primary source of light. In the days before electric lighting, skilled workers, such as craftsmen and artisans, often needed an assistant to hold a candle for them while they worked. 

Holding a candle was considered a menial task, typically assigned to an apprentice or a less experienced assistant. It was a basic duty, indicating that the person holding the candle was of lower skill and status compared to the master craftsman. 

The phrase "can't hold a candle to" emerged as a way to describe someone who was so inferior in skill or ability that they weren't even qualified to perform this simple task for someone more skilled. 

The phrase is believed to have originated in the 17th century. One of the earliest recorded uses of a similar expression is found in Robert Sanderson's "Sermons" (1681), where he writes: "You know the value of these men; you know how far they are from being fit to hold a candle to Aristotle."