In simple terms, a particle that has a positive surface charge is known as a positively charged particle. Similarly, any particle that has a negative charge on its surface is known as a negatively charged particle.
There are some fundamental particles: neutrons, protons and electrons and these make up all the atoms. Neutrons and protons are neutrally and positively charged, respectively, while an electron is negatively charged. The nucleus of an atom consists of neutrons and protons, while the electrons are found outside the nucleus. An atom is neutrally charged. However, when it loses an electron, it becomes positively charged and when it gains an electron, it becomes negatively charged. A positively charged atom is called a cation and a negatively charged atom is called an anion.
Thus, depending on the surface charge, we can classify any particle as either positively charged, neutrally charged or negatively charged.
Hope this helps.