The structure of a proton is more complex than a simple elementary particle. According to the current understanding in particle physics, protons are composed of smaller particles known as quarks. Specifically, protons are made up of three quarks: two up quarks (each with a charge of +2/3) and one down quark (with a charge of -1/3). The combination of the charges of these quarks results in the net charge of +1 for the proton.
However, it is important to note that the internal structure of a proton is not like a tiny "billiard ball" with distinct layers or components. The concept of "hollowness" does not apply in the same way it does to macroscopic objects.
Inside a proton, the quarks are bound together by the strong nuclear force, which is mediated by particles called gluons. The interaction between quarks and gluons is complex and involves the exchange of gluons, leading to the strong force that holds the quarks together within the proton.
Additionally, the energy associated with the strong force within the proton allows for the creation of quark-antiquark pairs and virtual particles that continuously appear and disappear within a very short timescale. These quantum fluctuations are inherent to the nature of particles and fields at the subatomic level.
In summary, the structure of a proton is best described as a combination of quarks, gluons, and the dynamic interactions between them. It is a manifestation of the underlying quantum nature of matter and the fundamental forces of nature.