Reality, frae Latin "res, rerum", meanin "the thing", is a philosophical conceipt that introduces the notion o reality, truith, suith. The opposite notion is "virtuality".
Ancient an modern notion 
- Far the auld philosophers, reality is whit exists in twa warlds : the ane o the essences, the ane o the empirism.
Far Platon, ye maun eschew apparent sensiblity, aye changin, far tae gang in Idea's warld, whilka foonds aw that exist in sensible warld. Oor kent warld is sae illusion Bat Kant considers that reality for Man is jast whit appears tae us; jast bein a phenomenon. Sae, he thinks reality isnae truith.
Vision o a makar 
The French makar Paul Valéry said ance: « Ma main se sent touchée aussi bien qu’elle touche. Réel veut dire cela, rien de plus ». It daes mean: "Ma hand feels the touchin o the things altho it touches. Reality daes mean that, naethin mair. The reflexion o the makar means sae that reality is jast the sensation o the things, jast whit we live in, without complex philosophical sochts or thochts.
Uise in physics 
Quantum mecanics, a branch o physics foondit in the early 20th century, haes establishit a number o hichly counterintuitive experimental results. Som individuals hae assertit those results are relevant tae a conception o reality. In particular, the experimental data suggests twa facts aboot the univers at gey small distance (on the scale o individual protons):
- 1. first, that the univers is non-deterministic, an
- 2. second, that the conceipt o an objective measurement is, strictly speakin, meaninless.
These twa truiths are interrelated bat worthy o separate attention.
Non-determinism o quantum systems fallows directly the Schrödinger Equation. This equation solves only far probabilities, not far determinate values. Far saumple: a child haes $5, an wants tae spend $2. The child asks his father haw much o the original $5 he will hae efter spendin $2, an the father tells him that he will hae $3 remainin. The father is uising the arithmetic tae offer a determinate prediction, whilka claims that if ye hae $5, and ye spend $2, ye'll haee $3. It is nae possible that ye will hae $1 remainin, it is nae possible that ye will have $6 remainin: the amoont o the remainder is determinit tae be $3.
In contrast, if the child asks whilka side a flippit clink will land apon (heids or tails), the anser is different. This anser is probabilistic, in that it is nae a specific prediction, bat a general claim aboot the results as a whol: the clink haes a 50% chance o landin on heids, an the same chance far tails. Practically speakin, this rochly means that the mair times ye throw the clink, the closer yer heids-tails results will get tae bein hawf o ane, hawf o the ither. It daes nae tell ye the ootcome far any particular clinks toss.
Photons as well as ither particles, hae been shawn tae possess wave-particle duality, meanin that their probabilistic nature is given by an oscillatin probability wave.