Yes, by definition, antiparticles can be categorized as the opposite counterparts of ordinary particles. Every subatomic particle in the Standard Model of particle physics has a corresponding antiparticle with the same mass but opposite charge.
For example, the antiparticle of an electron (an ordinary particle) is called a positron. The positron carries a positive charge, whereas the electron carries a negative charge. Similarly, the antiparticle of a proton (ordinary particle) is called an antiproton, and it has a negative charge while the proton has a positive charge.
In addition to opposite electric charges, antiparticles also possess opposite quantum numbers such as lepton number, baryon number, and strangeness, among others.
When a particle and its corresponding antiparticle come into contact, they can annihilate each other, releasing energy in the process. This annihilation is a result of the mutual destruction of particle and antiparticle, with their respective charges cancelling each other out.
The study of antiparticles and their interactions is an essential part of particle physics, and it has practical applications in various fields, including medical imaging (positron emission tomography or PET) and particle accelerator technologies.