Hello M4TE and welcome to Seven Forums. Sorry for the delay in responding but I just came across your question.
Most newer manufactured computers have a hidden recovery partition on the hard drive. The manufacturer provides specific instructions on how to access that partition in case you want to restore your machine to the exact condition it was in when it left the factory. That means you'd have to go through the time consuming process of cleaning out factory bloatware (like free trials of programs you'll never need), installing programs you do need, updating everything, creating your personal settings, etc. Here is a general idea of how to access the hidden recovery partition. HP Recovery From Partition
Let's say it took you a day or two to set up your machine to your liking using the hidden recovery partition. A System Image is like a snapshot of your entire hard drive. It will include everything from the operating system to all your programs, files, photos, music, all updates ... everything. Most folks keep it on a separate external hard drive. Let's say a week later you get a virus or your machine crashes for some reason. You can use that System Image to return your machine to the exact condition it was in when you made the image. Usually takes about 30 minutes or so and you're back in business. It's a lot faster and more convenient to only worry about a week of updates compared to probably months with the hidden recovery partition. The newer a System Image is the less you have to worry about.
But one caution: since a System Image is, for all purposes, an exact
duplicate of the hard drive, it will also include any malware that may be on the machine. So if in doubt, it might be best to use the hidden recovery partition to start off with a clean slate and then make a System Image immediately following all customizing.