Onedrive question

I recently replaced my 13-year old computer running Windows 7 with a new computer running Windows 11, which I don't really know anything about. Before shutting down the old computer I transferred My Documents and My Pictures onto a portable hard drive. After setting up the new computer I transferred those from the portable hard drive onto the new computer. I didn't know anything about OneDrive, which I now realize it seems to be cloud storage provided by Microsoft. The documents and photos I transferred easily filled up the 5gb I got for free with my new Microsoft account. They want me to pay for additional storage, but I'm not interested. I have plenty of room on the hard drive of my new computer. I am annoyed by the red X's next to files and documents, etc. on my computer. I believe I can get rid of them by going to settings and account in OneDrive and clicking on Unlink this PC. If so, will this unlink condition continue after I reboot the PC?

I also have a question about the files that are saved in OneDrive. It appears that those files are also still present in the PC. If so, that would be great. I can access them whenever I want and would be able to just ignore OneDrive, which is what I prefer. If that is the case, though, I don't understand the point of OneDrive. How is having files in OneDrive saving space on the computer if there are still copies on the PC? This is important for me to know that the files are present in both places. If they're not, it would be a hassle to transfer 5gb of random files back to the computer it seems. Since the computer is brand new I haven't generated any new files yet. I would consider just deleting every file on both OneDrive and on the computer, then transferring them again from the portable hard drive.

Thank you in advance for any information about this anyone can provide.

 

I disabled the sync and got rid of the red X's. Thanks for the reply.