Say, its only a paper moon
Sailing over a cardboard sea
But it wouldn't be make-believe
If you believed in me
"It's Only a Paper Moon" by E. Y. Harburg & Billy Rose
"It wouldn't be make-believe" -- as fiction writers, that's what we're trying to achieve. We take our ideas and our words, our "paper moon," and ask readers to believe in them enough to be drawn into our stories.
Something that can make this harder or even impossible for the reader is when we write something that makes them stop and say "Hey, that doesn't fit!" Recently, I was working on a story set some time in the not-too-far-off future; from clues in the story, it's reasonable to place it sometime between 2030 and 2050. My main character was responding to a scene of criminal mischief at a store. At first, I had her securing the "tape" from the security camera. Rather quickly, I realized that this didn't sound right, and I changed it to "memory card."
Is that a perfect change? Will we really still be using memory cards 30-40 years from now? No one can say for certain, but it's a lot more likely that we'll be using them than tapes. And coming up with a newer technology could be jarring in its own way. If I'd say that she retrieved a "quantum memory cube", well, it would certainly sound futuristic but it might also sound like nonsense. It was a minor detail in the scene and there was no reason to encourage the reader to focus on the technology being used for the security cameras.
This seems like an especially good thing to keep an eye out for during the revising process, or if you're beta reading for someone else. During the first draft, you may not catch this sort of thing, particularly if it deals with a minor detail. Catching it before you sending your work out for editors or paying customers is what's important.
Anything which you do that gives the reader that "Hold on!" moment keeps them from believing it your world, and makes it all to easy to remember that the moon is just paper hanging over a painted cardboard sea.