What is a particle (in the geological context)?

Question

When I look up the term grain size in wikipedia it says this: " Grain size refers to the physical dimensions of individual particles of rock or other solid". What does particle mean in this context?

Answer 1

Its size of grains that make up the composition if the rock. As an example: sand sized particles vs. gravel sized. A sandstone vs. a conglomerate.

Answer 2

A particle is an induvidually-eroded piece of rock/mineral. It ranges in size from giant boulders to clay sized partilces. Depending on size, it can be made of a specific rock type or a single mineral.