It's impossible to explain everything from the beginning. You might not be the target audience and the software/blog post was unwittingly posted. And sometimes, people just put things on the web for shits and giggles with no audience in mind. With no audience in mind, you don't feel the need to explain anything.
Anyway, HN fulfills that need. HN is widely-read that it's likely SOMEONE knows what the hell something is, and if often willing to give a summary. So if you're befuddled, just read the comments.