The framework in which quantum mechanics and
special relativity are successfully reconciled
is called quantum field theory.
It is based on three basic principles: two
of them, of course, are quantum mechanics
and special relativity.
The third one, which I wish to emphasize,
is the postulate that elementary particles
are point-like vibrations in quantum fields.
Remember the wave-particle duality?
Mind-blowing, right..?
Yea, forget about it.
In fact, there are no particles and no waves;
just fields.
Both "particles" and "waves" are merely two
ways in which we naively interpret quantum
fields.
There's one field for each type of particle.
So one field for all photons in the universe,
one field for all electrons, and so on.
And these fields exist everywhere.
To "extract" a particle from a field, you
need to give the field energy.
If you give it enough energy, the field will
go to a higher energy state.
These states are what we interpret as particles.
The point in the field where you gave it energy
will look like a particle, and as the energy
propagates through the field, it will look
like the particle is moving.
Some fields require more energy than others
in order to create a particle.
The amount of energy is proportional to the
mass of the associated particle.
For example, a Higgs boson is much more massive
than an electron.
So electrons are very easy to create, but
Higgs bosons are very hard to create.
You can go, for example, to the 
electron machine, pay some money, and get
an electron.
And then you can go to the photon machine,
pay some other amount of money, and get a
photon.
There are 18 such machines (that we know of).
According to QFT
Fields are everywhere
Particles are field vibrations
