The percentage of a rock’s total volume that has pores and spaces is referred to as its

Porosity

Explanation:

Porosity is defined as the total percentage of pore spaces that are present within a rock. These spaces are found between the rock particles and fractures and are mostly filled with fluid mixture or water. It is the ratio between the total pore space in a rock to the total volume of the rock. It is mainly calculated in terms of percentage.

Porosity is directly affected by sorting. Well-sorted rocks indicate high porosity but poorly-sorted rocks indicate low porosity. Some of the examples of rocks exhibiting high porosity are limestone, shale, and sandstone. Rocks with low porosity include granite and mudstone.