The difference between lava flows and fissures

The video explains the nature of lava flows during effusive eruptions, highlighting their varying sizes and speeds based on viscosity. It discusses how topography confines these flows and introduces volcanic fissures as linear vents for lava. Despite understanding magma flow directions underground, predicting the exact timing and location of fissure appearances remains challenging.

What are volcanic fissures and how do they differ from lava flows?

Why is it impossible to predict when and where fissures will appear?