Final answer:
Igneous rocks that form from the cooling of lava on the Earth's surface are called extrusive or volcanic rocks. They have a fine-grained texture due to the rapid cooling that doesn't allow large crystal growth. Basalt is a common example of an extrusive rock.
Step-by-step explanation:
The igneous rocks that form from the freezing of lava on the Earth's surface are known as extrusive or volcanic rocks. These rocks are characterized by their fine-grained texture, which results from the rapid cooling process that occurs when lava erupts and solidifies quickly. Unlike their counterparts, intrusive igneous rocks, which cool slowly beneath the surface and have coarse-grained textures, extrusive rocks cool so quickly that the crystals have little time to grow
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An example of an extrusive rock is basalt, which is often seen in volcanic regions like Hawaii. Observing basalt and other volcanic rocks offers insight into the dynamics of Earth's geological processes. Moreover, understanding the formation of various igneous rocks, such as the distinction between extrusive and intrusive, helps geologists trace the history of volcanic activity and plate tectonics.