Okay, so a web search and some looking around gives me https://www.honeycomb.io/frontend-observability. I guess this is something to do with tools for sending telemetry back from web applications and then doing statistics on them and giving the user some nice reports.

"Observability" seems like a weird term for that to me, but okay.

But I don't understand why not just give the appropriate context in the submission, rather than keeping a title that only makes sense to a very specific niche audience and then not saying up front what the niche is.

The concept of an "event" is coherent in many other programming contexts, so the possibility that one could be coherently "wide" is at least plausibly interesting. But then I get there and find myself completely disoriented, and eventually figure out that it's not actually relevant to anything I do. And anyway it looks like a lot of this jargon is really just not necessary to convey the core ideas... ?