Cantrips are a type of spell in Dungeons & Dragons that a character can cast without using spell slots or components. They are essentially spells that a character has practiced so much that they can cast them almost anytime and anywhere. Cantrips are the simplest and weakest spells available to learn, and they are generally the most common uses of a characters magic. They are also known as "zero-level spells". Cantrips have relatively weak effects compared to other spells, but they can be cast every turn without expending any resources except for the action it takes to cast them. Cantrips are weaker than spells that take up spell slots, and they typically have effects such as casting a Fire Bolt or summoning something with low HP such as a Mage Hand. In summary, cantrips are a type of minor spell that a character can cast repeatedly without using up resources, and they are the simplest and weakest spells available to learn in Dungeons & Dragons.