Pooled mining is a mining approach where multiple generating clients contribute to the generation of a block, and then split the block reward according the contributed processing power. Pooled mining effectively reduces the granularity of the block generation reward, spreading it out more smoothly over time.
The mining pool coordinates the workers. It’s just like a lottery pool. Your odds of winning a lottery are very low, so you team up with a bunch of other people and agree to split the winning. This makes your odds of winning much higher, but the amount you win much lower.
Anyone who wants to make a profit through cryptocurrency mining has the choice to either go solo with their own dedicated devices or to join a mining pool where multiple miners and their devices combine to enhance their output.