Reality, daydream, fantasy or RP

Reality

The myth of the cave:
In this allegory, people are chained from birth in a cave where they see nothing but shadows created by others. Plato asks us to imagine how those who are chained can learn about and come to accept true reality. This story illustrates Plato’s theory of knowledge, truth and education.
People chained in the cave = Those who, knowing no better and having no opportunity to know better, accept phenomenon as reality. What they perceive, they interpret as real.
Plato (430-347 B.C.)

Daydream

Freudian psychology 
interpret daydreaming as expression of the repressed instincts similarly to those revealing themselves in nighttime dreams. Like nighttime dreams, daydreams also are an example of wish-fulfillment, based on infantile experiences and allowed to surface because of relaxed censorship. He pointed out that in contrast to nighttime dreams, which are often confusing and incoherent, there seems to be a process of "secondary revision" in fantasies that makes them more lucid, like daydreaming. The state of daydreaming is a kind of liminal state between waking (with the ability to think rationally and logically) and sleeping.
Freud (1856-1939)

Fantasy

Traits of fantasy
The identifying traits of fantasy are the inclusion of fantastic elements in a self-coherent (internally consistent) setting, where inspiration from mythology and folklore remains a consistent theme. Within such a structure, any location of the fantastical element is possible: it may be hidden in, or leak into the apparently real world setting, it may draw the characters into a world with such elements, or it may occur entirely in a fantasy world setting, where such elements are part of the world. Essentially, fantasy follows rules of it's own making, allowing magic and other fantastic devices to be used and still be internally cohesive.
Wikipedia

RP

Two or more people writing a story together
RP stands for Role Play. It's a type of writing which usually happens between two or more people. and it is notoriously hard to finish a single story before starting a new one. Each person takes on one central character as their character, and then accepts responsibilities for several or many others depending on how many people are participating in the RP. However, the more people,the harder it is to keep organized and controlled.Traditionally beat and easiest between two writers. One person starts, the other replies, the first reply to the reply etc. Often taken on in the writing community between two people who are close friends, or else is used as a way fir writers to get used to another person'e style. When two people participating in the RP know one-another very well, it's often possible to distinguish what their reply to a certain situation will be, and can therefore be anticipated a d detailed before it even happens.
Urban Dictionary