Viscosity is a measure of a fluid's resistance to flow. The higher the viscosity, the thicker and more resistant to flow the fluid is.

Basaltic lava is typically characterized by:

* Lower silica content: This results in a lower viscosity, making it flow more easily.

* Higher temperature: The higher temperature reduces the viscosity of the lava.

Rhyolitic lava is typically characterized by:

* Higher silica content: This leads to a higher viscosity, making it flow more slowly.

* Lower temperature: The lower temperature increases the viscosity of the lava.

In summary:

* Basaltic lava: Low viscosity, flows easily.

* Rhyolitic lava: High viscosity, flows slowly.

Therefore, basaltic lava is less viscous than rhyolitic lava.