Jargon is hot garbage and is often a signalling technique to show who's in the circle and who's out of the circle. That you are in the circle and doesn't understand this is an issue doesn't make it not one.
I'd suggest a slight correction: Jargon outside of specialist spaces is hot garbage. It can be absolutely essential within those spaces to communicate clearly, collaborate, and get work done.
Note that the OP is struggling to turn jargon into language that his player can understand.
And, I'd like to commend @innerdude, because to my eye they did a pretty solid job of it! Yes, it took more verbiage than if jargon was used, but it was clear and understandable to anyone who plays RPGs.