Science is built on a bedrock of trust, which typically involves sharing enough details about how research is carried out to enable others to replicate it, verifying results for themselves. This is how science self-corrects and weeds out results that don’t stand up. Replication also allows others to build on those results, helping to advance the field. Science that can’t be replicated falls by the wayside.
At least, that’s the idea. In practice, few studies are fully replicated because most researchers are more interested in producing new results than reproducing old ones. But in fields like biology and physics—and computer science overall—researchers are typically expected to provide the information needed to rerun experiments, even if those reruns are rare.