A related concept is liability. Suppose you're a service provider - a contractor who performs maintenance services. You sign a contract with your client, BigCo, where you will service their plant's fancy $1m machine every month, and in return they pay you a modest $500 per month. One month you make a mistake in your work which causes their machine to become defective, but you & they don't notice in time before the defective machine creates a large mess. The defective machine causes BigCo to lose $3m due to lost revenue while the machine is offline & their costs to replace the machine. There's a pretty good chance BigCo may be able to sue you for the $3m losses they suffered from your mistake, even though this is disproportionately higher than the value of your $500 / monthly fee. As the contractor you avoid or limit this by making sure there is language in the contract to limit your liability & maybe arranging an insurance policy.

Now, how do things change if you sell a software product instead of a service? & how do things change if you give that software product away for free, instead of selling it? There's still a chance that some user of your free open source software product suffers real harm because of it. Particularly if they're using your free software in a commercial context with a lot of scale, perhaps they've suffered millions of dollars of losses because your free software product was defective. Are you liable to compensate them for their damages? Maybe!