Here's a breakdown of the terms:

* Pyroclastic material: This is a general term for any fragment of volcanic rock, ash, or other solid material ejected from a volcano during an eruption.

* Tephra: This is a more specific term for any airborne fragment of volcanic material, regardless of size or composition. Tephra can range from fine ash to large volcanic bombs.

The size and composition of pyroclastic material can vary depending on the type of volcanic eruption.

Here's a breakdown of common types of pyroclastic material:

* Ash: Fine particles of volcanic glass, rock, and minerals.

* Lapilli: Small, pea-sized to walnut-sized fragments of volcanic rock.

* Blocks: Large, angular fragments of volcanic rock.

* Bombs: Rounded or streamlined fragments of molten or partially molten volcanic rock that are ejected from the volcano and solidify in flight.

Important note: While the terms "pyroclastic material" and "tephra" are often used interchangeably, there's a slight distinction:

* Pyroclastic material emphasizes the solid nature of the debris.

* Tephra emphasizes the fact that the debris is airborne.

Hope this helps!