From the point of view of Husserlian Phenomenology the answer to that question is somewhat complex.
There is an assumption in Western Philosophy since Kant that there are Synthetic A Prioris that we Intuit in our perception that in fact we ourselves project prior to our perceptual experience. Kant mentions Space, Time, and the Categories which are then Schematized in Time. Since Kant we have learned that Space and Time are one thing from Einstein, so that means that schematizations and categories must be the same thing, and also Space and Time that are singularities that are separate in Kant must be the same singularity. So from a Kantian Point of view we are projecting A Priori syntheses based on our manufacture and elaboration of the spacetime singularity and the category/schemas. It must be also that the these two levels are also really one thing, but Kant suggests that although we project spacetime it is really the objective spacetime of physics that we are connecting to in that projection. The real manufactured projection is in the category-schemas that we project concerning the phenomena that occurs within the envelope of spacetime. Bernstein in his regressive reading of Kant in his lectures on the internet (bernsteintapes.com) says that the mistake Kant makes is thinking that there is only one type of time, and thus only one type of space which is linear clock driven time and objective Newtonian space. It should be noted that Kant’s philosophy is based on the structure of Calculus and so it uses the math that Kant and Leibniz discovered to structure our approach to questions such as the one being answered now but also to give a basis for science and to support the idea of objectivity by rooting it in subjectivity, and thereby showing as Bernstein says there is no transcendental Reality without Transcendental Idealism. The whole thrust of Kant’s argument according to Bernstein is precisely this, that we can only know objective reality if there is a root in transcendental subjectivity. Perception of reality is therefore based on our own projections of Synthetic A prioris via Spacetime as a singularity and Category Schemas that govern the relation of form and content in experience that we perceive and then apperceive (conceptualize).
Hegel introduces dynamism and history into this picture, and goes beyond it to define another level of projection which he calls Absolute Spirit, which is basically the wholeness of the intersubjective cohort’s development of its projection capacity unfolding in history. In other words mind/ghost/spirit the projector evolves though the vicissitudes of history via dialectical cancellations and syntheses of different philosophical approaches to experience.
Husserl, goes back to Kant and attempts to build up a way of talking about pure phenomena, i.e. what we actually experience in our consciousness when we think about phenomena. He begins with the Intentional Morphe forming Hyle into objects of sense. Here the projection of the Intentional Morphe as an A Priori Synthesis of the Kantian type is presumed. But when we intuit back those perceptions of objects in experience we find that there are noema and noesis and that these are not pure. So Husserl says that perception and apperception is in fact also an interval or spectrum and at one end of that spectrum there is a lot of meaning with little hylic content and at the other end of the spectrum there is a lot of hylic content and little meaning.
Then Husserl talks about the noematic nucleus, which is what you see that is constant as you look at the same object from different perspectives. Now this is the external coherence of the object from a phenomenological perspective. But he goes on to talk about how we have an intuition of the essence of the object which is different from our perception of it. This essence intuition is an insight into the kind of the thing within its synthetic manifold. This insight into its kindness is different from perception and is an insight into the internal coherence of the thing. The essence is seen as a constraint on the attributes of the thing. If you violate the constraints on those attributes then you have something else but not the particular kind of thing that we intuit in terms of kindness. So we have insights into the kindness of things around us directly and that is different from either the perceptions of the noematic nucleus or the projections of noesis onto the thing by interpretation. Crucially these are not simple ideas; an abstraction is a completely different thing from essence (eidetic) intuition. And this insight of Husserl of this difference becomes in Heidegger the difference between the modes of Being of Dasein as being-in-the-world, called present-at-hand and ready-to-hand. Being itself has separate modalities that are related to Abstraction on the one hand and Essence intuition on the other hand. With Heidegger we can say that there are at least two equiprimordial modes of Being which I call Pure Being and Process Being. One conceptualizes theoretically and is related to Pure Reason and the other has circumspective concern and relates to practical reason governing the whole of technology as we create artificial designed entities to support our activities in the world.
Now Heidegger according to Walton is drawing on the later genetic phenomenology of Husserl in his crafting of Being and Time. Heidegger distanced himself from his teacher by relating his phenomenology in Being and Time in Hegel and Aristotle (read phenomenologically). But the fundamental idea of separating the modes came from Husserl’s late unpublished genetic phenomenology which was dynamic and unfolding in history rather than static like the earlier phenomenology. So we have here an example of Husserl going from Static to Dynamic conceptualization which is seen in the switch from Bracketing to seeing objects on the horizon of the world. Heidegger takes this idea of the fact that all things are seen on the horizon of the world and turns Husserl’s Phenomenology upside down, but evidently this idea was originally Husserls in his later genetic phenomenology. And so that means that the only originality of Heidegger was finding a way to talk about things before the subject/object split, i.e. in terms of Dasein which projects the world in which it finds itself. This is the same paradox as appears in the trinity in Christianity in which the Son as God finds itself in the world created by the Father as God, and the relation between these two aspects of God (Persons) is of course Spirit. Heidegger explicitly says that Dasein is Hegel’s Spirit at one point. In other words the spirit is the bridge between the Son in time and the Father in endless time and of course all three in Christian Theology are Personas of God which are united yet different. The Son in the world (in spacetime) confronts objects created by the Father who is in eternity. What is between the two is the spirit that bridges this gap which is neither the Son nor the Father, but something that the two share, seen concretely as an angel who comes to Mary to announce the virgin birth of Jesus. So in Being and Time Heidegger is confronting the central paradox of Being, i.e. that we project the world and we live in it at the same time according to transcendental idealism which is the dominant philosophy of the Western tradition because it is the only way to avoid the conundrums posed by the skeptic Hume.
But the key point that Husserl makes in his later genetic phenomenology is that we do not need to bracket experience to discover the phenomena, which produces the problem of intersubjectivty and the noumena which Kant confronted. Rather by realizing that there is a furthest schema, the world on the horizon of which all things appear, one may use that horizon as the means of situating the phenomena and thus we do not need the bracketing, and our phenomenology can become dynamic rather than being static dealing with things like the unfolding of history for subjectivity as part of an intersubjective cohort evolving a culture as a living society through time.
Now we come to the key point needed to be understood to answer this question. Once we realize that there is a furthest schema in experience, i.e. the world and all forms show up on the background of this furthest schema, then we can see that Reality means that for any object of perception of which we have an apperception (concept) and of which we have an eidetic intuition (essence intuition) there must be an infinite horizon of exploration associated with it. In other words real things are things that can be infinitely explored phenomenologically. Reality which is the limit of that infinite exploration of any phenomena can only be substantiated by continued exploration that pushes toward an infinite limit and does not find a stopping place on that journey. Most things we do not explore deeply but we gloss them in abstractions and are content with our essence intuition of them as we look at them in terms of our own purposes. But reality is there as an aspect of Being, along with Truth, Identity and Presence. What we explore must in some sense be Present to us as sensations that we turn into perceptions of an object. Phenomenology starts with what is Present, but Heidegger includes the traces of what is absent in his phenomenology. The combination of apperception (concept) which gets turned into Ideas which are abstract glosses and essence intuition allows us to identify phenomena. And when we describe the phenomena in language then we can make our statements about it True if there is a correspondence between what we say and what we experience.
So what Husserl discovered which was leveraged by Heidegger was that reality is merely the limit of infinite exploration of some phenomena in experience on the horizon of the furthest schema, i.e. the world horizon. And in this sense Kant was right about there being a tie between Transcendental Realism and Transcendental Idealism, and as we see this involves the use of the analogy with calculus and the idea of the limit. Reality from a phenomenological perspective is merely the limit of our exploration of a phenomena, and things that are not real cannot be explored infinitely but have limits in this exploratory process that they impose, rather than that we impose. Because we are finite beings the things we make that are artificial normally have these thresholds at which new information does not come from further exploration, but natural phenomena are not like that, they have truly infinite horizons of exploration in themselves. For us there may be limits on our wanting to pursue that exploration, rather we just explore enough to ground our activities, and then we leave it schematized. See Umberto Eco Kant and the Platypus for the history of schematization in our tradition.
My own contribution to this subject comes from the invention of General Schemas Theory, which to my surprise seems not to have occurred to anyone previously. It asks the question as to what is the next emergent level up from Systems Theory, and that must be something that talks about Monadic Content, Pattern, Form, System, EcoSystem (meta-system, openscape), Domain, World within experience. These are ontological emergent differentiations of our projections A Priori as opposed to ontic a posteriori emergent thresholds like quark, particle, atom, molecule, macro-molecule, virus, cell, multicellular aggregation, organelle, organism, social group, ecosystem, Gaia. Bernstein said that Kant’s only mistake was thinking that there was only one kind of time or space. And General Schemas Theory suggests that we project a number of different mathematical and geometric schemas upon experience and that they have some interesting structural interactions which show up in Science and different approaches to phenomena. But the key is that you can project different schemas on a particular ontic level of phenomena and thus have different templates of understanding as the a priori synthetic projects are fundamentally different between the various schemas that nest with each other to cover the whole scope of experience.
This question you have raised has become central within our tradition, and what has been discovered is that only Transcendental Idealism can answer it fully without falling into the traps of skepticism such as those raised by Hume. But to answer Hume a very complex structure based on calculus had to be built by Kant, elaborated by Hegel, articulated more finely by Husserl, and transformed by Heidegger, in order to get to the understanding of the answer to that question that we have today, from the point of view of European philosophy (so called Continental Philosophy which is just European philosophy carrying on within its own tradition, rather than the schismatic pseudo tradition called Analytical Philosophy, which is really an anti-philosophy, or skepticism about metaphysics in general, originally).