Today, we take the term "open source" for granted, but this wasn't always the case. There wasn't a single, universally accepted term to describe software that was freely shareable. "Free software" was one of the terms used, but it wasn't clear to non-programmers how this was different from proprietary software that was downloadable without having to pay for it. If you're not a programmer anyway, how should one type of "free software" be different from another?

Proponents of what we now call "open source" wanted to distinguish between two senses of the word "free". One sense is not having to pay for something, as in "Come over to my party, the beer is free." Anther sense is "I can criticize the government, because the country I live in is free." People in the free software and open source movement began to phrase the dichotomy in these terms to illustrate how one sense of the word "free" is much more important than the other. The fact that you don't have to pay for some piece of software is nice, but what's more important is that you aren't beholden to the company that developed it.

https://en.wikipedia.org/wiki/Gratis_versus_libre

I too struggled to understand this when I first came across it.

Free to use vs free to do what ever you want with

Something that costs you nothing versus a freedom.

Tell me you’re young without telling me you’re young.