Here's a breakdown:

* Texture: This refers to the size, shape, and arrangement of the crystals within the rock. Textures can be:

* Phaneritic: Large, visible crystals, indicating slow cooling.

* Aphanitic: Small, microscopic crystals, indicating rapid cooling.

* Porphyritic: A mix of large and small crystals, indicating a change in cooling rate.

* Glassy: No crystals, indicating very rapid cooling.

* Vesicular: Contains holes (vesicles) from trapped gas bubbles during cooling.

* Mineral Composition: This refers to the specific minerals that make up the rock. Different minerals form under different temperatures and pressures, so the composition can indicate the rock's origin. The most common minerals in igneous rocks are:

* Feldspars: (plagioclase, orthoclase)

* Quartz

* Pyroxenes

* Amphiboles

* Olivine

Combining Texture and Composition:

These two factors are used together to create a comprehensive classification system. For example, a rock with large, visible crystals of feldspar and quartz would be classified as a phaneritic granite. A rock with small, microscopic crystals of pyroxene and olivine would be classified as an aphanitic basalt.

Let me know if you'd like more details on specific igneous rock types!