A Beowulf cluster is like a bunch of friends working together on a big project. Imagine you and your friends are working on building a big tower of blocks. If you tried to build it alone, it would take a very long time. But if you all work together, the tower can be built much faster.
Similarly, a Beowulf cluster is a group of computers working together on a big task. Each computer in the cluster is called a node, and they can all talk to each other and share information. When a big task comes along, like doing complex calculations or running a simulation, the cluster can divide the work up between the nodes, with each node taking on a little piece of the job.
This allows the Beowulf cluster to get the job done much faster than a single computer could on its own. It's like building that tower of blocks, but with all your friends helping out, it gets done much faster and with less work for each person.