Let me tell you, what is an electron? And how can you know this?
An electron is an elementary unit for charge. This is only known because of extremely precise measurements taken near the beginning of the 20th century. We knew nothing about electricity or magnetism before. We know very little about these things due to observable effects. As a fundamental unit for charge, electrons were first discovered. They have mass and it is common to determine the electron’s charge-to-mass ratio in undergraduate physics labs. We know electrons have charge and mass. They also have spin (a magnetic dipole moment). We know very little about electrons, as they have all of the properties we can easily detect.
People jump to conclusions about the electron’s nature because they lack descriptive knowledge. Many physics books use small, round images to identify electrons. You need to take the time to see what you actually know and not just what you imagine.
The electrons are considered particles. However, the most important property of an electron is its ability to be detected locally. Photons can also be detected locally. Light, however, is considered a wave. Most people consider photons particles.
Why is the role of particles in physics so important? They embody the principle if locality. Local interactions are compatible with the principle of relativity, and can lead to causal orderings.
However, interference experiments can be done with light to illustrate its wave nature. Single photons can be detected as particles, however. Is that possible?
It is impossible to answer this other than to state that it is what has been observed. Photons behave quite similarly to electrons. They can also exhibit interference.
These seemingly incompatible properties led to quantum theory’s development. The theory simply describes these observed properties. The theory doesn’t try to explain these properties, but it embraces them and gives a mathematical description. This is all that we expect a theory should do. Quantum theory’s predictive power is the key to its success. The majority of the fundamental particles could be predicted long before they were discovered. Antimatter was predicted long before it was discovered. These are just a few of the many successes of quantum theory. The theory does not explain what something looks like, but it does describe what we can expect to see.
It is therefore more useful to dispel preconceptions about what particles are. They can be detected locally and have a few properties. They are not solid balls. They can also be detected at a local level, but that does not necessarily mean they can’t be detected elsewhere. Quantum theory says otherwise.
This is the end of the story. “How” requires a reference point. This is what we see things to be.