Caption: A cartoon illustrating the wave-particle duality of quantum mechanics.
Features:
How much here or there is its "density of being"---which is just a useful nonce expression.
Conventionally, the "how much here or there" is called a probability distribution, but that may NOT be exactly right as we discuss below.
The capital Greek Psi = Ψ (pronounced Psi like sigh) is the common symbol for the wave function.
The "density of being" itself is the QM probabilitiy density which is equal to the square of the complex-number absolute value of the wave function: i.e., = |Ψ|**2.
The QM probabilitiy density is, among other things, the probability density for measuring a particle at any point in space.
The ħ (pronounced h-bar) is the reduced Planck's constant ħ = (1.054571817 ...)*10**(-34) J-s = (6.582119569 ...)*10**(-16) eV (exact values) (see NIST: Fundamental Physical Constants --- Complete Listing) (which is a universal physical constant that first turned up in quantum mechanics) and k is the mean wavenumber.
k=2π/λ where λ is the mean wavelength.
A wavelength is the length of one complete up-and-down cycle.
The megaminds have been divided on many interpretational issues in quantum mechanics---and have been since Albert Einstein (1879--1955) and Niels Bohr (1885--1962) had their iron-cage grudge matches on the them.
But it doesn't seem to matter how we interpret quantum mechanics---it works just fine no matter what we think of it.
See Schlosshauer et al., 2013, A Snapshot of Foundational Attitudes Toward Quantum Mechanics.
Yours truly jests---polls are pretty common in science before the evidence solidifies---but with quantum mechanics, the evidence never solidifies.