Called 草字头 cǎo zì tóu in Chinese, the Chinese radical 艹 cǎo is the modern form of the character 艸, which is nearly no longer used. What an evolution, from the wavy 艸 to the straightforward 艹! Both forms look like two strands of grass sticking out of the ground, don’t you think?

艹 is a character meaning component

艹 is a very frequent meaning component in Chinese characters. You’ll find 艹 in characters and words related directly or indirectly to grass and plants.

These characters all contain 艹 and have a direct link with plants:

草

cǎo

 grass

The component 艹 can also be found in words that aren’t directly related to plants.

艹 is a very common element in Chinese characters and you’ll find it sometimes in characters that have nothing to do with plants.
There is no common rule you can follow concerning these exceptions, and often, history and the evolution of the Chinese character over time is behind these exceptions.
Therefore, to know why some words contain 艹 but are not related to plants, you’ll need to look up the word’s etymology and historical background. Some words used to be related to grass or plants but aren’t anymore. Despite that, they kept the element 艹.  For other characters, it’s just their simplified form that uses  艹. When you check their traditional form, you’ll quickly see there’s no  艹 in the character’s composition. In brief: for some characters, you’ll need to explore to understand the presence of 艹 in them!