There are a large amount of different types of gravel available.
From decomposed granite, ½” or ¾” multicolor rainbow, Brown landscape. ⅜” , ⅝” & 1 ½” and larger bull rock, ¾” blackstar, Mexican beach pebbles (Moon rock) various sizes, ⅜” to 1” white limestone.
Typical installment includes grass or weed removal, grading, add sand if needed, weedmat, edging such as, chop rock or 4” steel, or 4” composite edging, then the gravel.