"Hi. How're you?"
"Good! It's Friday."
The number of things contained in just two words - "It's Friday" - is huge. "It's Friday" and I'm really looking forward to sleeping in tomorrow. "It's Friday" and that means I don't have any meetings, which pleases me. "It's Friday" and I like the casual jeans day.
It's not quite jargon, really, but certain words and phrases acquire meaning. "It's Friday" is probably pretty darn common. Others will be specific to your workplace and your job or product. These phrases and words are shorthand for a lot of context and allow you to communicate quickly and effectively... as long as you're in the know.
For example, one of our coded phrases is "large directory." Now, if you google "large directory", you get a whole lot of nothing. But for us, it had a specific meaning: a single directory containing many inodes, where many is typically considered over 2000 but in context may be over 20,000. So when we're working with services to size a deployment, or helping support with a problem at a client site, we can simply ask, "Are there large directories?" and proceed based on that information. It's a fast, easy way to say something that would otherwise take a while to clarify.
Over time, this accumulation of phrases and shortcuts becomes part of your company's institutional memory. Spread it wide enough and you've got jargon. Don't shy away from the shorthand, though. Just make sure you can explain it to others, and then embrace the efficiency!