Point Particle
1. A point particle is an idealization of particles heavily used in physics.
2. A point particle is a perfect body whose dimensions are equal to zero, we can also consider the size of the body is infinitely small compared to other dimensions.
A point particle is an appropriate representation of any object whose size, shape, and structure is irrelevant in a given context. For example, from far enough away, an object of any shape will look and behave as a point-like object.
In quantum mechanics, the concept of a point particle is complicated by the Heisenberg uncertainty principle: Even an elementary particle, with no internal structure, occupies a nonzero volume. For example, a 1s electron in a hydrogen atom occupies a volume of ~1030 m3. There is nevertheless a distinction between elementary particles such as electrons or quarks, which have no internal structure, versus composite particles such as protons, which do have internal structure: A proton is made of three quarks. Elementary particles are sometimes called "point particles", but this is in a different sense than discussed above.
Corrosion Dictionary https://www.corrosionpedia.com/dictionary
YourDictionary https://www.yourdictionary.com/
En-Academic https://en-academic.com/dic.nsf/enwiki/