I open skp and skb at same time and i save my work but my file doesnt change at all, please help🙏🏻
You would never open an skb file, but might occasionally rename it to .skp and then open it.
Understanding how they work together is worth it. When you start a new file there is no skp and no skb. When you first save, there is an skp, but no skb. When you save a second time, there is now also an skb.
The skb is a duplicate of your previous save. If you work on the model for a while, and save, and then decide you hate your recent changes, that’s when you might throw away the skp, and rename the skb to skp, to get yourself back to where you were earlier.
Another time you might do that is if your skp gets corrupted. You could try the skb renamed, and just lose an hour or two of work, but there is also Auto Save. Those files are saved somewhere else, and if you open SketchUp after a crash, you should see a ‘Recovered’ version of your file. That’s the auto save version.
So, skb will never look like the matching skp, unless you intentionally do a couple of consecutive saves where the model is the same. For cases where the skp cannot open, try the auto save version before renaming the skb.