Romance is along fictitious narrative in the form of verse or prose, which was used to be written in the Middle Ages. Romance deals with supernatural, romantic, amorous and heroic adventures of characters. It also deals with knights, courtly love and chivalry. In modern age, it refers to a narrative wherein imagination is the key element and which is not based on reality. Many of romances were written about King Arthur and his knights. Sir Gawain and the Green Knight is an example of early English romance in verse. Malory’s Morte D’ Arthur is a prose romance.
What is romance, you ask! Romance is more fleeting and more dangerous than we are told, more complicated than we could have imagined, more elusive than we've been led to believe. Yet it is pursued more readily by most because of its raw reward. It is the ultimate response to a popular stimulus.
A genre of fiction centered around the budding, dwindling, or ongoing intimate relationship between a core group of characters, with the events of the story being shown through that filter. This genre is typically one that requires a humongous amount of talent to write, so of course that means 95% of the material you find under that label is absolute tosh.