Eugen Golstein discovered many important things in science, including anode rays and the proton. After discovering anode rays, which are streams of ions that are produced from specific gas discharge tubes, Goldstein worked with many different gases, including hydrogen.
There is some confusion as to whether Goldstein identified that hydrogen ions were protons because the mass to charge measurements that identified protons were not made until later by Wilhelm Wien.
The proton is one of three atomic particles that all atoms can contain, along with electrons and neutrons. A single proton contains a positive charge of 1. Protons are important in fields of science, in particular chemistry and physics, that try to understand how particles interact.